Version: (using KDE KDE 3.5.5) Installed from: Ubuntu Packages OS: Linux How to reproduce: Get an imap account with "load on demand" activated. Send yourself or get email with a big attached, that will at least take a few seconds for you to download. For test purpose use a openoffice or text file so that you can see the result clearly (fill that file with whatever data of course). quit kmail so that the attachement is not in a temp file, start it, and open the big attachement. While it is downloading (see the progress bar), switch to any other mail wait until the attachement opens in the background. when it finally open, you will get a blank file without contents. I could reproduce this on different distributions also running kde 3.5.5. Of course, disabling "load on demand" is a work around for this. Thanks :)