There was a default in one version of the Liberty toolbox where it automatically decided which apps would install to phone and which would install to SD card.
I had the same issue. There is a file that gets created on the SD card when you load apps to it. This file causes issues with updating certain apps, Angry Birds being one of them.
Sure fire way is to back up your SD card files to the PC, Titanium Backup files regenerated the issue for me. Format the SD card. Load only what you need back to it and install apps to the phone. Make sure your ROM doesn't put apps on the SD card. I've never run out of space on my DX and the Apps to SD creates issues.