Between mid-Friday and about mid-Sunday the EU server you were mining on didn't get anything. That would explain some of the low payouts for Monday and Tuesday.
dam server was ok most of the time but with very low payout (and not a lot of unexchanged coins to be payed later)
Payout were about 0.006 BTC/d/Mh for me yesterday. That's quite low compared the 0.011 to 0.015 that I usually got on eu server.
Payout, compared to other users' with similar hashrate, is very low. Some of them got more than twice mine. Other got similar payouts, probably other european users mining on Amsterdam and/or Ireland servers.
It looks like if the good switch algo we had on Irish server till the end of January has been replaced by a new experimental and not so efficient algo...
...and moved on US servers ?