ok - a couple of pointers for those having problems:
1. NTFSDOS is known to have issues with this process. Either use a known working Floppy disk or much better option, a bootable USB stick. If neither are an option, get something like Partition Magic and resize your main PCs NTFS partition so you have a couple of hundred meg left at the end. Create a FAT32 partiton in this area and copy your files to this location instead. Then boot from a floppy/CD (not NTFSDOS) and go to the C drive (which will be the first partition it can read - your FAT32 partition). Try running it again from there.
2. There's an option on iPrep to force the menu:
Make sure it's ticked. If it still doesn't ask you for a choice, make sure you have at least one other drive connected (IDE or SATA, it doesn't matter). As long as MTKFlash can see it, it'll ask you to choose. Pick the option for XTREME Pri Master. If it still stops at 00%, try again after a reboot and follow the MS28 'bad flash' procedure just in case.