well I just uninstalled Avast so I could ship (so obviously I meant UPS Worldship - should have said that in the 1st place, sorry) :'(
I was using free avast and I think it was 5.1.864. I use Windows XP
I was not getting any error messages AT ALL - when I clicked the UPS icon, absolutley nothing happened. When I called UPS tech support, they told me this was a known problem, that avast was blocking the executables & I should go into avast & list several exceptions (exclusions) and that should (hopefully) fix the probem. It didn't. Also, turning off Avast while trying to open UPS also did not seem to help.
The problems started yesterday afternoon (1/5) - immediately after I upgraded my UPS Worldship to the mandatory software for the 2011 rates. NOTE - I had also been on the 14.x UPS Worldship beta test for the past few months, with no incompatability issues during that time.
Other than this, I have had no problems with avast & am sorry that I had to uninstall it & now have to find another AV program