I have $10,000 and am not in the blinds. It's $200 to call. I raise $600. I mouseover the "raise" button and it correctly says $800 ($200 to call, plus the $600 raise). However, after I click the button, I see that my cash remaining is not the expected $9200, but rather $9000, meaning I put $1000 into the pot rather than $800.
In a different hand, I have $9700 and am in the small blind. Somebody calls $200 and I decide to raise. I move the slider up to $600. I mouseover the "raise" button and it correctly says $700 ($100 to complete the blind, plus the $600 raise), for a total of $700. I expect my cash total to be $9000, but instead it's $8900, meaning I put $800 into the pot instead of $700.
It looks like when you raise, it adds 2x the amount to call plus the raise, when it should add only 1x.
This bug has been around for a very long time now. I'm rather disappointed to see Poker Night 2 coming out when Poker Night 1 doesn't even work properly.