IB data should not be used to back-test. The general event handling of the IB API is a note of concern even for automated trading.
Open-Tick = Free = You get what you pay for.
Many good sources of back-testing data, but you must subscribe or pay.
How to rate a programmer by price.
Free = I want to steal your idea
< $25 = I don't speak english to well and good luck finding me after I have your cash
< $50 = I will give you an estimate but after I miss it, you wish you paid for a better programmer
< $100 = I double all my hours...
http://cm-videos.com/public%20videos/01-2007/Jan08-Clients/Jan08-Clients.html
No sales in three months so he quits (maybe because his method don't work).
How can he blame piracy when his videos are available for free on the internets???