Hi
Yours was the in-app upgrade, right?
You'll probably need to uninstall & reinstall the latest free version
https://market.android.com/details?i...ullsoft.winamp
As long as you are logged into the same google account that you originally made the purchase with,
then it should automatically upgrade to Pro.
Note that this issue should be addressed in the next release so you don't keep losing Pro status and have to reinstall.