I've also been seeing these problems... (1) missing Last and Change columns and/or frozen quotes. I can usually fix this with ctrl-alt-T to re-connect. (2) runaway javaw.exe process under Task Manager. This is due to a looping java thread that causes... (3) Daily log c:\jts\log.*.txt growing very large with repeating java exceptions. I've got some this week over 15GB in size! If you're seeing all three issues, you're seeing the same problem as me. It seems to happen most often between 9:30 - 10am when the servers are most busy. Looks like a problem with the TWS client requesting a new market-data row and losing part of the response, but that's a guess because it seems to only happen after I've added market data lines. Re-starting TWS is the only way to kill that javaw.exe process, but TWS still works ok, albeit very slowly, while that javaw.exe process is busy. I think the quotes aren't really frozen, just updating *very* slowly. This happens on multiple TWS versions; I don't think it's a client problem. Anyway, I have a ticket for this. I expect a response from IB sometime this year.