Hi,
you can too free memory with specific software like "hibernate", included in most cooked ROMs.
Personally to be sure don't have problem, before starting a training I make a soft reset and close what I don't need ie Mobile Shell or other...
One problem I experienced with Mossis ROM is that when I first start Run.GPS and then take some photos during a training, Run.GPS gets always closed by Windows Mobile. This is because of the Windows Mobile strategy that when memory is lacking other programs are shut down no matter if they have unsaved data.
Solution: Close or uninstall as many applications as possible, e.g. "UltimateLaunch".