That is possibly the most annoying problem with flashpoint.
I managed to get it to stop by:
1. Right click on the OFP shortcut and select 'Properties'
2. In the 'Target' box by the top, put the following code, instead of the one thats in there already
"C:\Program Files\Codemasters\OperationFlashpoint\FLASHPOINTRESISTANCE.EXE" -nosplash -nomap
3. Click apply, and test it
That worked for me.
Of course, if you don't have resistance, use this
"C:\Program Files\Codemasters\OperationFlashpoint\FLASHPOINTBETA.EXE" -nosplash -nomap
/\ I think /\