Unfortunately I have the same issue with deposit ETH from BITSTAMP.
Bitstamp uses contract transfer, so it is internal ETH transfer. This type of transfer is Liqui not able to process. The ETH are on Liqui ETH deposit address, but not credited to your wallet.
THIS IS SERIOUS ISSUE!
The worst is that my support ticket #25312 about this problem is processed for 18 days(!) without any reply.
Very sad.
UPDATE: after 22 days they replied: "We will check it." and that was 4 days ago...
I don't think Liqui is a scam, they simply do not have ETH contract transfer implemented and terrible support, so DO NOT send ETH from BITSTAMP!
I've tried another ETH transaction from standard MEW and it went smooth.