app bundle runs in script editor, hangs standalone

i’ve got a dvr scheduler that’s been working great for years as an app: it reads .tvpi files & maintains crontab events to record off a firewire tuner.

i’ve been extending it with a web interface & eyetv scheduling, and i’m running into a hang when it reads the .eyetvsched files, but only as a stand-alone app:

if i run the same code in the script editor, it works fine:-\ anybody got suggestions on how 2 debug this? i have put display dialogs that have shown the problem occurs somewhere in the

tell application "System Events"
set pInfoFile to property list file etvFilename...

the problem exists both in 10.6.3 as well as 10.4.11…