Hadn't noticed this much before but it could be long-standing.
Recently updated java at the apple web site. Machine says it runs java1.5.0
I tried playing with the java plugins in preferences to fix the problem without success. Are you aware that three java plugins are running in OW5 simultaneously? One is new and two are old.
Here is an url which disappoints in OW5 for a famous web game called "rush hour:"
http://home.hetnet.nl/~fredvonk/rushhour.htm
In general I've been resorting to safari4.0.1 when omniweb bails. I can't quibble with minor problems in good free software. I still prefer this to safari because of the interface. I have a 77 year old in the house who will only browse with OW5 because it has been customized for her user identity and she is extremely proficient with OW5. thanks again for a great product. I used to pay for this :)