When starting-up in FC4 I get these advises:

"hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
hda: dma_intr: error=0x84 { DriveStatusError BadCRC }
ide: failed opcode was: unknown
hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
hda: dma_intr: error=0x84 { DriveStatusError BadCRC }
ide: failed opcode was: unknown
hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
hda: dma_intr: error=0x84 { DriveStatusError BadCRC }
ide: failed opcode was: unknown
hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
hda: dma_intr: error=0x84 { DriveStatusError BadCRC }
ide: failed opcode was: unknown
hdb: DMA disabled"

I have read a lot of things about this problem but no solutions. The hard disk is quite OK. What does dma_intr mean?

With hdparm I get:

"/dev/hda:

Model=ST3120022A, FwRev=3.06, SerialNo=3JS1NFDE
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=unknown, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=234441648
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2
AdvancedPM=no WriteCache=enabled
Drive conforms to: ATA/ATAPI-6 T13 1410D revision 2:

* signifies the current active mode"

I see that nothing is marked with *. I see also that there are not dma modes but mdma and udma.

Any ideas?

Everytime I have seen errors like that, it has been bad hardware. Not neccessarily a bad drive: the most common source of those errors has been bad cabling, in my experience. I've once had a bad mobo detected that way (the other IDE channel, I learned soon, wouldn't show up at all).

Check your cables and connectors if you believe the drive to be good. It might be worth testing the drive with smartmontools to check up on its health (something that one should do periodically anyway).

Finally I have fixed the problem. I don't know if this solution will be valid for other people, but I write it.

My hard disk fits the norm ATA 100, that uses ULTRA DMA 5 mode and can get up to 100 MB/s of transmission speed. The adecuate cable for it is the IDE of 80 wires and I had the IDE one of 40 wires. I changed it and the problem is gone!

Saludos, amigos.

That'll do it. 40 wire ATA cables are only certified for ATA/33.