I have two things to say on your situation.

1. By chance was you touching any part of the screen when you attempted to click the other buttons, because the screen does support multitouch but I have learned that this is only in curtain areas and it you touch any part of the screen while tring to select a menu it will not work. Try it, touch a open area of screen and then try to click a button, I am sure it wont work.

2. When they flashed it to 2.2 did they reset the device and you lost everything or did they just installed it over the 2.1 and all your information was stilll in the phone when they handed it back to you?  I ask because the update seems to cause issues when just installed but device information wasnt wiped first,  Try This:

This has been verified as being the best way to stop a number of the issues that has developed after doing Froyo update, the system seem to keep the 2.1 app and settings during installation process and this seems to cause a number of incompatible issues with a number of devices.... Follow this process after completing Froyo Update to avoid problems..

Follow these settings during restore to avoid issues being restored automatically.

1. Uncheck "Back up my data" under Settings/Privacy

2. Click Factory Data Reset/Reset Phone

3. After reset is complete only Active Phone but do not input Google Email information

4. Once phone is at homepage go back into Settings/Privacy and make sure the Automatic Restore option is unchecked, even if grayed out, activate "Back up my data" and quickly disable "Automatic Restore"

5. After being sure that the Automatic Restore option is off it will be safe to log into Google and you can continue installing preferred apps and custom settings.

This process will stop all applications and settings from restoring automatically and restoring original issues that usually resolve a number of issues.

Funny it look like me and Ann154  is on the same page on this subject