you could try the cs9 update for PTLE7.4:
7.4cs9
Why are you still on 10.4.1? I don't have any info about OSX updates that might be causing the problem, but that version of the OS is at least 3-4 years old. If you can do so without creating other problems for yourself, you might want to update to 10.4.11.. I'm just thinking that 7.4 might have never been tested with that old version of Tiger. Maybe Digitechsupport could comment on this...
If you do update OSX, then use the COMBO updater, NOT software update...