My Pool history (more or less, looking at the transactions and from what I remember):

From the 9th to the 13th: - happyminers.net.
From the 13th to the... 13th: -Cryptopools.com
From the 13th to the 15th: - pooljunkie.nl.
From the 15th to the present: - dedicatedpool.com

So, happyminers crashed, then they changed the server from S2 to S3. They still have coins in the old server, s2.happyminers.net (just log in and check it out) 
Cryptopools crashed, got all my coins out.
Pooljunkie crashed. Not fully payed. Give my remaining coins back 
Dedicatedpool. No issues, just a bit slow confirming blocks.

That's about it.