WHy BTC-e prices different from Bitstamp? IS there no effective arb avaliable or what?
At the moment, BTC transactions are unreliable.
In general, BTC-e is a less trustworthy reliable exchange than Bitstamp and traders/investors are less inclined to want to do business there.
So far, Bitstamp is the only major USD exchange that has shown no obvious signs of being hacked (so far) or subject to ultra crooked insider trading.
BTC-e had the $100 flash crash where lots of peoples orders weren't filled.
Bitfinex had the $10K price spike, followed by the $100 flash crash.
MtGox...well, we all know very well about MtGox who have had a long history of general dodginess which is now being brought to its inevitable end.