I obeserved today a phenomenon
Suddenly my stales rate went drasticaly up allso the whole machine was lagging badly, im not sure about what did cause that, i could not find any activities in my logs so that wasnt caused by any apache related activity, just p2pool and the chains was running. I suspect that this has something to do with peers; this could be intentionaly or cause of a bug. i realized that stales and orphaned shares on the p2pool operating chain are probably caused trough this.
got the same problem.
my DOA increased to 40-50 %.
using bitcoind 6.3.
investigated that my ztex-boards caused the problem. for some reason java took 100% of all 4 cores.
did a reboot and every thing is fine now.
Did this per chance happen at midnight 12 AM on the 1st of July? There was a leap second adjustment that has caused all kinds of problems. The solution is to reboot the computer that is having issues. This max CPU usage is something I have heard developers in other non Bitcoin related IRC channels mention.