It's been said many times that uswest (middlecoin.com) is less profitable than useast. I can only assume that means it is also less profitable than eu since eu and useast are both supposed to be running the new beta software (while uswest is running the older). Try making eu or useast your primary based on latency.
That's one of your problems right there. Don't use the old main middlecoin.com as your primary. It (and USWest which is currently identical) is on old code that's been less efficient than what's on the new beta servers. H2o has plans to update that one too and have Middlecoin.com be a front for all the regional servers that will give you the best location for your relative latency, but this hasn't been implemented yet, so for now if you want best returns, you should connect to the beta server closer to you.
Try setting your cgminer to the EU, USEast, or Asia beta servers with whichever server gives you the best sustained ping (lookout for spikes over a minute or so pinging) as the primary.
From where do you guys get the idea that uswest/middlecoin.com would be running older code? Nothing of that sort has been said. It's not running older code, it's running the exactly same code. The other servers are beta because they're not 100% stable, hence the servers themselves are beta, not the code they are running.
I'm basing it on one of H20's last posts here...
The US server now has the new code, which doesn't disconnect on coin switches. It's bugged to have 1% extra rejects, which show up as "duplicate shares".
Of course that could also mean he subsequently pushed that code to the the non-beta server too...but why do that if he was going to replace middlecoin.com with the front-server that would switch you to your regional server eventually anyway. I know I wouldn't change the existing stable server until all the beta's are done and then I would update it. But you're right, that part is definitely an assumption. H20 hasn't said either way.
But USEast (and EU and Asia) are definitely on a new and different codebase than what was there in December.