OK, but is there any way to put the "sck 10" into a command line option for a script?
If I understand correctly, issuing that command causes it to be written to EEPROM in the avrispmkII, so it should be a one shot deal.
FYI, on a recent project I flashed and verified a 7k program in a few seconds from a PPC powerbook, so what you are seeing isn't normal (but I think you already knew that 
). I was burning directly from the powerbook's USB port, while on battery even.
You may also want to check the firmware on your avrispmkII.
-j