Index: applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java
===================================================================
--- applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java	(revision 13667)
+++ applications/editors/josm/plugins/wmsplugin/src/wmsplugin/GeorefImage.java	(revision 13673)
@@ -58,5 +58,5 @@
             return false;
         }
-        
+
         // Width and height flicker about 2 pixels due to rounding errors, typically only 1
         int width = Math.abs(maxPt.x-minPt.x);
@@ -64,9 +64,9 @@
         int diffx = reImgHash.width - width;
         int diffy = reImgHash.height - height;
-        
+
         // This happens if you zoom outside the world
         if(width == 0 || height == 0)
             return false;
-        
+
         // We still need to re-render if the requested size is larger (otherwise we'll have black lines)
         // If it's only up to two pixels smaller, just draw the old image, the errors are minimal
@@ -79,20 +79,54 @@
 
         boolean alphaChannel = Main.pref.getBoolean("wmsplugin.alpha_channel");
-        Image ppImg = image;
-        if(!alphaChannel) {
+        // We don't need this, as simply saving the image to RGB instead of ARGB removes alpha
+        // But we do get a black instead of white background.
+        //Image ppImg = image;
+        /*if(!alphaChannel) {
             // set alpha value to 255
             ppImg = clearAlpha(image);
+        }*/
+
+        try {
+            if(reImg != null) reImg.flush();
+            long freeMem = Runtime.getRuntime().maxMemory() - Runtime.getRuntime().totalMemory();
+            //System.out.println("Free Memory:           "+ (freeMem/1024/1024) +" MB");
+            // Notice that this value can get negative due to integer overflows
+            //System.out.println("Img Size:              "+ (width*height*3/1024/1024) +" MB");
+
+            // This happens when requesting images while zoomed out and then zooming in
+            // Storing images this large in memory will certainly hang up JOSM. Luckily
+            // traditional rendering is as fast at these zoom levels, so it's no loss.
+            // Also prevent caching if we're out of memory soon
+            if(width > 10000 || height > 10000 || width*height*3 > freeMem) {
+                fallbackDraw(g, image, minPt, maxPt);
+            } else {
+                // We haven't got a saved resized copy, so resize and cache it
+                reImg = new BufferedImage(width, height,
+                    alphaChannel
+                        ? BufferedImage.TYPE_INT_ARGB
+                        : BufferedImage.TYPE_3BYTE_BGR  // This removes alpha, too
+                    );
+                reImg.getGraphics().drawImage(image,
+                    0, 0, width, height, // dest
+                    0, 0, image.getWidth(null), image.getHeight(null), // src
+                    null);
+                reImg.getGraphics().dispose();
+
+                reImgHash.setSize(width, height);
+                g.drawImage(reImg, minPt.x, maxPt.y, null);
+            }
+        } catch(Exception e) {
+            fallbackDraw(g, image, minPt, maxPt);
         }
-           
-        // We haven't got a saved resized copy, so resize and cache it        
-        reImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
-        reImg.getGraphics().drawImage(ppImg,
-            0, 0, width, height, // dest
-            0, 0, ppImg.getWidth(null), ppImg.getHeight(null), // src
+        return true;
+    }
+
+    private void fallbackDraw(Graphics g, Image img, Point min, Point max) {
+        if(reImg != null) reImg.flush();
+        reImg = null;
+        g.drawImage(img,
+            min.x, max.y, max.x, min.y, // dest
+            0, 0, img.getWidth(null), img.getHeight(null), // src
             null);
-
-        reImgHash.setSize(width, height);        
-        g.drawImage(reImg, minPt.x, maxPt.y, null);
-        return true;
     }
 
@@ -124,5 +158,5 @@
 		return out_img;
 	}
-    
+
     public void flushedResizedCachedInstance() {
         reImg = null;
Index: applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java
===================================================================
--- applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java	(revision 13667)
+++ applications/editors/josm/plugins/wmsplugin/src/wmsplugin/Grabber.java	(revision 13673)
@@ -53,4 +53,5 @@
         g.drawString(tr("Exception occurred"), 10, height()/2);
         image.image = img;
+        image.flushedResizedCachedInstance();
         image.failed = true;
         g.setFont(font);
Index: applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSGrabber.java
===================================================================
--- applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSGrabber.java	(revision 13667)
+++ applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSGrabber.java	(revision 13673)
@@ -56,6 +56,8 @@
             image.max = proj.latlon2eastNorth(b.max);
 
-            if(image.isVisible(mv)) //don't download, if the image isn't visible already
+            if(image.isVisible(mv)) { //don't download, if the image isn't visible already
                 image.image = grab(url);
+                image.flushedResizedCachedInstance();
+            }
             image.downloadingStarted = false;
         } catch(Exception e) {
Index: applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java
===================================================================
--- applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 13667)
+++ applications/editors/josm/plugins/wmsplugin/src/wmsplugin/WMSLayer.java	(revision 13673)
@@ -172,4 +172,5 @@
                     img.downloadingStarted = true;
                     img.image = null;
+                    img.flushedResizedCachedInstance();
                     Grabber gr = WMSPlugin.getGrabber(baseURL, XYtoBounds(x,y), Main.main.proj, pixelPerDegree, img, mv, this);
                     executor.submit(gr);
@@ -250,4 +251,5 @@
                     GeorefImage img = images[modulo(x,dax)][modulo(y,day)];
                     img.image = null;
+                    img.flushedResizedCachedInstance();
                     img.downloadingStarted = false;
                     img.failed = false;