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.