OmniWeb crash on wake from sleep

Hi,

I'm having this problem with OmniWeb 5.1.3: when I wake the computer  
(PowerMac G5 dual 2-Gig) from sleep and OmniWeb was opened, it will  
crash 3 times out of 4. I've tried deleting the preferences and cache  
files, but the problem won't go away,

This wasn't happening in previous versions. I haven't tried the new  
beta versions of 5.5, so I don't know if it was fixed, assuming it's  
not a problem specific to my setup.

Any ideas on a solution?

Thanks.

-- 
Martin Nadeau