LyX 1.5.0 won't start properly on Mac

[Bennett Helm]

LyX 1.5.0 cannot be started by double-clicking the LyX.app icon on  
Mac: it crashes immediately. However, starting LyX from the command  
line (or via gdb) works with no problem. So I'm a bit limited in the  
debug info I can produce. Here's what Console.app prints out:

Wrong command line option `-psn_0_96993281'. Exiting.
mcount: gmon.out: Permission denied
Any idea what's going on?

Bennett