"Random" AppleScript errors on startup and on various actions

Hi,

I am using PictureSync for turning iPhoto tags into IPTC/XMP keywords. (I know, this is not its main purpose, but I did not find any other program for the Mac that does this job.)

Since a while, when I start PS, the application does not respond for a long time and then displays this error message:

System Events got an error: AppleEvent timed out. (-1712)

After another delay, it then displays:

Can’t get «class defE» "id" of «class useD». (-1728)

Now the menu bar is active; however, when I try doing something useful, I only get more AppleScript errors. For example,

PictureSync > About PictureSync:
Can’t get «class defE» "skip" of «class useD». (-1728)

File > Open Selected:
"" doesn’t understand the prep message. (-1708)

PictureSync > Preferences > Save:
missing value doesn’t understand the itemOfList message. (-1708)

I checked the Known Bugs section and ensured that nothing of the listed issues applies (ie, I have no SIMBL installed, I use no multibyte language, I have no old preferences in ~/Library/Preferences/com.holocore.PictureSync.plist (this file actually does not exist).

I also tried to fix this by reinstalling PS from a freshly downloaded dmg but to no avail.

Is there anything else I can check?

Thanks,
Christoph