Hi There
Old post i know, but
I had the exact same issue and although i didnt find out how to set preload, but I did manage to setup my chipset settings to eliminate the issue.
Basically set the Main Chip Mem to "2MB" and the the Z2 Fast to "256KB" and 32-bit Chip to "128MB"
Note: leave Slow and Z3 Fast set to "none"
This has completely resolved for me (although loading initially takes quite a while to load)
