Every now and then, you may get two executions while changing an order without hitting the "T" letter. But TWS usually reports as two fills.
Quote from PuffyGums:
In the C:\JTS directory, the msgIn.t and msgOut.t files contain all the FIX messages you sent and received. Unfortunately its is erased everytime you log into TWS, so you need to copy these files and save them. Should give you some info when you contact customer service.
I have gotten double fills when trying to modify an order during a spike. They showed up in my execution reports and total position windows.
What is the price bug you are referring to?
(Looks like I might start archiving msgIn and msgOut files as regular practice.)