i also changed from eu to useast.
it works there.

But after a while i changed it back to eu and now it also works there.

EDIT: i removed workername aswell.
EDIT 2: i think something got stuck at eu server.
switching to useast and back to eu server fixed it for me.

mining with two rigs on EU server:

rig 1: seams OK

rig 2: cgminer accepting shares
but the stats website states 0 kH/s and 0 accepted shares!

I also restarted cgminer on both rigs.
the rigs are mining on different Bitcoinadresses

around 2.5%
ping is good 70ms

yesterday it was below 1%