PDA's in flight

Anyone else running XC flight software on a PDA find them to be
sluggish and almost unuseable during a flight? I am using an iPAQ 3850
running XC-Soar, the unit is hooked to a Garmin Map60CS. Sure
everything works, but while in the air, if I push a button or touch
the screen somtimes it takes several seconds for the function to work.
This often leads to stacked commands that eventually cycle thru, but
inevitably end up not on the command I wanted/needed.

Case in point: Mountain XC flight the other
day.....................middle of the Cascades and I am wanting to
look up my alternate airports/LZ's.............it is almost impossible
to get the PDA/software to do this. Instead I just used the GPS, which
has the same data the PDA has.

Is there some setting on the PDA to speed things up? I know there is a
setting to allocate more memory to the programs....could that be
tweaked?

Thanks,
Brad