[amibroker] Backtesting Index...No Results

[David Fitch]

Can someone tell me why individual backtest yields no results for most indexes. 
These begin with a "^" in front, ^DJI. A few do work,ie ^FVX,^IRX,^TNX,^XAL.  
But most show no buys/sells. This is EOD data.
Thanks
Dave