I too get Fatal Alert - MemeoryMgr.c, Line:3751, Free Handle when code that opens a Datalog file executes on Palm Tungston E2.
after several test, i finish by understand. I use the vi PDA memory usage.vi and i look the palm memory increased always.
then i use PDA memory compact.vi for free the memory but after test the vi don't operate.
I use this vi on an other palm (T5 and T3)and it is good.