How to debug " fatal content error has been detected" in webplayer.

Any suggestions on how to debug webplayer crashes? I checked the Webplayer.log and all it say is

120306 23:16:08 Setting error display: ‘The content was stopped because a fatal
content error has been detected.’, details: ‘The content was stopped because a fatal
content error has been detected.’, link: 0

hundreds of time per second. I have checked development build and turned on debugging. It all runs fine in the editor. It used to run fine in web player. I did a lot of development to make it look better on iOS and then some more web persitance stuff and now a crash and no way to find any details.

It is not crashing right after any particular action and following the same play in webplayer cause crashes at differing times.

Cheers,
Grant

see this and install full webplayer
full version