I also had some problems logging in earlier today... When I clicked "Manage Funds" it logged my out. It is sort of working now (at least it works some times
Are you running a bot? It may cause login interference since we jacked up the security settings.
You were also correct about the fractional quantity on orderbook. You can place a sell order for 1 Bitcoin, but if someone buys on 0.995 bitcoins, you will have a fraction sitting on the orderbook. We have removed the rounding and reduced minimum trade quantity, so you will see more if these fractions sitting on the orderbook.
Hope this helps,
EDIT: Just saw your follow up post. Never mind!