What is MaxTransfer ?
Some IDE drives have problems with high MaxTransfer values, they seem to "choke" on large blocks of data if they are sent by the controller in one gulp. SCSI drives should run with any MaxTransfer, I haven't had any problems with them.
By the way, the MaxTransfer value is hardly important for the disk performance - a value of 0xFFFFFF means "16MB maximum in one transfer" while a value of 0xFFFF is still 64K. It was reported that somebody once set it as low as 2K and the loss of speed was hardly noticeable.
Follow this link for instructions on selecting the MaxTransfer value.