30 GB drives: Sonnet Tempo ATA/66 card conflict? Or is it the drive itself?

Sonnet Tempo ATA/66 cards mey be incompatible with at least some drives larger than about 30 gigabytes. Tim Thomas was told by Sonnet tech support that they did not test the card with drives larger than 30 gigs and do not yet have a handle on the problem. Tim writes: "I bought a Tempo ATA/66 card to use with a Western Digital 45 gig ATA/66 drive. Although the drive could be initialized and mounted, it appeared to have only a little over 30 gigs available. After trial and error tests, I was told by Sonnet tech support - who had previously said they thought the drive would work - that they never tested larger drives and did not know what was going on. They said they would get a WD450AA drive and test it, and that they would contact Acard (the card's manufacturer) in an effort to resolve the problem. I've since returned the WD 45 gig drive and picked up a Maxtor 30 gig which is working fine." Update: John Strung replies: "I wonder if this is really the card's problem. There have been several long-standing threads in MacFixIt's Troubleshooting Hardware forum about people without such cards having difficulties formatting a 40 gig Maxtor drive to anything larger than 32 gigs (see one and two for examples). The problem seems to be the some Maxtor drives are shipped with jumper settings restricting them to 32 gigs because of a problem with some PC's bios which will not read drives larger than 32. Removing the J46 jumper has been reported by some people to have solved the problem."