Recently I had a problem with the Ford Flash PCM recalibration software running in Windows XP. The error reported was "Cannot allocate memory". I beleive IMHO that this is because of the way that Windows XP allocates memory, or rather the way it doesn't. Previous versions of Windows allocate memory based on the Base, Upper, Extended memory separations. Windows XP groups all of the memory together in one big category. When using this program, i beleive that it looks for a specific memory range to flash the calibration to, and in Windows XP this memory range may be pointing to anything but the PCMCIA card.
FIX: Use Windows 98. upon reversion to Windows 98, the program works perfectly.
i hope that this can help anyone else having difficulty with this situation.