carlosvzz,
I've now done exactly as the MoSync method and ensuring that r21 tools were not downloaded. In addition to Android 2.3.3 api SDK Platform, I downloaded Android Support Library & Google USB driver as they were selected by default. However, I still had the same problem with AVD Manager. I'm baffled. I'm using Ubuntu 32 bit Precise. Any ideas?
I installed .Net2 & .Net2sp1 & .Net2sp2 using winetricks. I'm using Wine 1.5.2 from the Ubuntu Wine Team's ppa so that I could install .Net2sp1 & .Net2sp2. Did you install .Net2sp1 & .Net2sp2? Also, what version of Wine are you using?