There should be a smiley with egg all over its face! I'm sure that when I installed Sygate Pro firewall, I disabled the XP built-in jobbie. But when I looked a short while ago, there it was enabled again! (duh). Now it's disabled, I've increased the timeouts for uploads, and checked that the appropriate ports in Sygate are open. Now, MX is running, and we'll see if folks are able to access my files. Thanks a great big bunch for all your helpful advice thus far, folks, and I'll keep you all posted. (I'm not so concerned about my downloads taking forever - there's a few somewhat rare tracks a-waiting - but to get 8,031,480kb of a 8,263,091 file and then not be able to complete in three weeks is a bit much.)