The RPC code in the newest SVN version r115 is still not working right. Connections go up and down all the time with lots of idles. Maybe revert it back for the time being? I can do that by hand of course if need be but it's a bit of a hassle to maintain.

FWIW, the phatk2 kernel is exactly as fast as the r115 phatk kernel on my 6990. I measured over 24 hours with one of them on the first and one on the second GPU core of that card; there was no significant deviation in the number of shares produced by each core, less than 10 shares difference.