LinuxQuestions.org - dma issue with hard disk

Hi,
I installed FC-5 on my Acer Laptop...and DMA is not working. I had same issue with FC-4 and Gentoo and was able to sort it out..using following methods:

1. in FC-4 with 2.6.12 kernel..i had to edited the file piix.c and removed SCSI support from kernel and DMA was working after that.

2. With Gentoo Vanilla kernel -2.6.15. The code which i used to edit was completely removed...so this time i removed ATA support altogether and added SCSI support..this time my device IDs got changed from /dev/hdc to /dev/sda after this change. So i edited the fstab file and was able to work with Gentoo. But managing gentoo was taking lot of time for me..so i switched to FC-5 and here again..i tried to do the same stuff...but the kernel aborts when it comes to the step of finding root device..i guess device IDs have changed here also..(from /dev/hdc to /dev/sda), but the problem is fstab has only lable entries for partitions so i can't probably edit that also. In gentoo raw partitions name were there...so simply changed them.

But what do i do here? Also..once the device IDs gets changed to new ones...i guess i have to give permissions to normal users...so how do i that in FC-5.