If you use the Safari browser on Mac OS X, you may find that the 60-second browser timeout is shorter than the amount of time it takes for high end cache regeneration and synchronisation functions to be acknowledged (you may also be experiencing timeout issues with other websites using the safari browser). Repeating the submissions may not resolve the problem due to a 60 second timeout setting within Safari.

To overcome this issue you may want to install SafariNoTimeout (http://www.unsanity.com/haxies/snt), a free extension that will increase the 60-second timeout to 10 minutes.