I think I made a mistake.

I got a livetime Gold licence and MM3 installed with AAC encoder plugin. Unfortunatly, my iPhone 3GS has been updated o IOS5, so I must update to MM4, but I installed it to another partition to avoid breaking my MM3. I installed Codec Pack, but when I want to synchronize to iTunes, MM4 tell me now that I cannot encode my FLAC files to AAC now.

What could I do to resolve this problem ?
In advance, thank you for your help.

Best regards