I've had a support ticket open for while now. The Line 6 tech said that they'd been in contact with Apple and the Apple said that the 10.0.1 update was supposed to address the issue, but it didn't help me.
FWIW, they'd asked me to perform the following steps to completely uninstall/reinstall. I'd be interested to see if anyone else had any luck using this process. Please don't do this unless you've got backups or feel comfortable with the steps:
-Throw away all versions of POD Farm 1 or 2 applications to the trash from the Applications/Line6 folder.
-Manually search in the following locations and delete any of the files found from within each of these folders:
-Library/Frameworks (look for L6WXTG and L6WXTY.framework and delete them)
-Library/Application Support/Line 6
-(Username)/Library/Application Support/Line 6
-User/Library/Preferences (Line6 preferences, should be something like com.line6.xxxxx, etc. Delete.)
-Empty the Trash.
-Next, go into Applications/Utilities and launch the Terminal application and type the following commands at the prompt:
cd // (then press the enter key)
cd /private/var/db/receipts (then press the enter key)
sudo rm -i com.line6* (then press the enter key)
-Enter your Mac OSX account password. Note: you will NOT see the cursor acknowledge any characters being input; you will need to type your system password correctly and hit "Enter"!
-Type Yes to every option/question to remove Line 6 software components (there will be a good number of confirmations, FYI).
-Repair disc permissions using the 'Disc Utility'.
-Restart the computer.
-Download and install POD Farm 2.56 from the link below:
MAC POD Farm 2.56:
Once POD Farm 2.56 is installed, close all other applications and launch the Line 6 License Manager application and de-authorize and re-authorize your UX1 making sure to 'remove' and 'install'. Close License Manager and than open Garageband and try again to insert POD Farm 2.56 as an effect.