When does tester close orders?

 
I've been backtesting a strategy and on August 10th 2006 around 16:00 GMT, the tester will close my order, even though there's no reason for it to according to my EA. It then opens a new one and then closes it almost immediately, so for that hour, I have over 20 trades. Why would it do this?
 
- If the tester reaches end of data, it closes all open trades before making the report.
- If the eod isn't reached on August 10th. it can be a false tick (it is very common if your data hasn't been cross checked) triggering stops, or closing routines. Check the price, where the orders are closed, and check visual mode.
 
Please explain more about this "false tick".

Has anyone noticed trades in the tester outside of the trading range (high/low)?