Yes, I'm persistent.
I've found that with a -g 1 it does not happen anymore (it's been running for half a hour now), but I loose a couple Mh/s.
spiccioli.
ps. I had to install curl since it's not installed in linuxcoin by default.
BTW, cgminer found 128 as optimal worksize, but using -w 256 gives me 3-5Mh/s more juice, steady

So now I'm forcing it to -w 256 ( and -g 1 -I 8 -w 256 -Q 2 ).
It is running at 361 on my 880/270 5850 and 444 on my 980/280 5870
spiccioli.
MH rate gets irrelevant at the point where shares/minute come to play, I can get +10MH with -I 14 but -2 shares/minute, 128 or 256 doesn't make a difference in terms of shares/per minute, got one rig with 3 5850s and one with 1 plus a 6950... after a couple of hours the 3x does ~1080MHs/s ~15 shares/min @"-w 256" and the other with "-w 128" does 729MHs/s ~10 shares both with "-I 8". It might do a difference in the hashrate but the shares/minute seem to be stable at the same rate after a couple of hours.
cards compared directly are about the same "U" but different hashrates...
1+1!=3