I use TWS and the DDE for excel API. It's pretty basic stuff: I pull mainly current price data into the TwsDde.xls file and then into my own spreadsheet to track and monitor trades the way I like. I don't even use it for order execution. I was forced/urged to upgrade to the latest TWS build (910.9) a couple months ago and since then the excel file hangs as soon as I click "request market data". Can't seem to figure it. Downloaded latest API, got fresh TWSdde.xls file, etc etc. TWS itself works fine. Anybody else run into this problem and solve it? Running Windows 7 x64 (I had previously had issues with TWS when I upgraded to Windows 7 back in June, but that's fine now). Thanks!