I'd been using version 0.41o for a little while and as of about a week ago for some reason Sunrise now refuses to convert any of the URLs I've set up. I am getting the error "java.io.IOException: Buffer underflow while reading index file:null" on every URL. Upgrading teh 0.41p did not help.

I am using Windows XP SP2 and have plenty of disk space and memory on the system.

Any idea what's causing this?

The download cache has become corrupted. Delete the "cache" subdirectory in the ".sunrise" settings directory and restart Sunrise. This will recreate the cache.

On a WinXP system the directory is usually located here:

C:\Documents and Settings\<username>\.sunrise\cache

This did the trick. Thank you Laurens!