When using the backtester there are many instances of selling a stock due to the stop criteria and then buying it again because it qualifies
Back tests should be prevented from selling and buying of the same stock on the same day. Perhaps a set number of trading days before it can qualify again.
Larry, try using the Limit Repurchsaes feature in the BackTester. You can set it to not purchase the same stock for the next # of days that you specify. It is under the More Settings tab in Automation Rules.
Each set of automation rules in your test can be set this way. Look under More Settings in the area for duplicates. By default the slider will be set to 'not buy any stocks I currently own'. If you move the slider, though, you can have your rules dictate that a stock can't be bought until it has been out of your account for certain number of days... Give us a call if you're still having problems