Anaconda/Sata_Promise conflict?

I have 2 systems running Fedora Core. Each is a K8V-SE Deluxe motherboard with onboard PDC2037 (FastTrak 378/SATA 378) controller chips. One system has a Athlon 64 3200+ processor and the other a 3400+. Each has two 160GB IDE primary (hda/hdb) drives. Also two 160GB IDE (PATA) drives connected to the promise controller in IDE mode as sda/sdb drives. Drive /dev/sdb on each system has two Linux primary partitions and a swap partition. On system 2 (3400+), I have FC5 on hda6 and FC6T1 on hda8. FC5 & FC6 both have sdb1 & sdb2 mounted using fstab entries. FC5 was an upgrade from FC4 and FC6 was a new install. System 1 (3200+) has FC5 on hda6. I had to manually upgrade from FC4 because Anaconda fails when I select upgrade with an error saying it can not mount /sdb1. I tried the FC5 and respin FC5 cds with the same error. It would not put the abort dump info on a floppy no matter what I tried ether! That is another story. I tried FC6T1 and it gives an error right after I select "upgrade hda6" saying it could not mount sdb1 and says there might not be a file system on the partition. I deleted the sdb1 partition and created a new one and created a new ext3 file system on it. Still the same error. From FC5 I can mount the partiton and read/write it with no problems. So why is Anaconda complaining? I can stop the error by removing the entries for sdb1 & sdb2 from the fstab file under FC5??? System 2 is almost exactly the same and gives no error on upgrade selection with the fstab entries in place. What else can I try? What is at fault here? Any help to debug this would be appreciated.