[Karmic] Frequent freeze on Dell D810

System : Dell Latitude D810, Karmic with latest updates as of now.
The system freezes rather frequently when either plugging/unplugging the DC adapter, or resuming from suspend. When frozen, the HDD led stays lit.

* When the freeze occurs after resuming from suspend, it often results in a hard lock (magic SysReq keys have no effect). Sometimes, though, it just freezes for around 30s-1min, and then unfreezes. In these cases, pressing the caps lock/num lock keys correclty affect the indicator leds. In these cases, I usually find messages like this in the syslog:

Jul 13 17:15:36 tadzim kernel: [ 4025.000165] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
Jul 13 17:15:46 tadzim kernel: [ 4025.000189] ata1.00: cmd c8/00:08:9e:11:af/00:00:00:00:00/e0 tag 0 dma 4096 in
Jul 13 17:15:46 tadzim kernel: [ 4025.000193] res 40/00:80:00:00:00/00:00:00:00:00/40 Emask 0x4 (timeout)
Jul 13 17:15:46 tadzim kernel: [ 4025.000201] ata1.00: status: { DRDY }
Jul 13 17:15:46 tadzim kernel: [ 4030.040181] ata1: link is slow to respond, please be patient (ready=0)
Jul 13 17:15:46 tadzim kernel: [ 4035.024183] ata1: device not ready (errno=-16), forcing hardreset
Jul 13 17:15:46 tadzim kernel: [ 4035.024275] ata1: soft resetting link
Jul 13 17:15:46 tadzim kernel: [ 4035.206724] ata1.00: configured for UDMA/100
Jul 13 17:15:46 tadzim kernel: [ 4035.206746] ata1: EH complete

* When the freeze occurs when plugging in the DC adapter, parts the desktop are responsive, apps that are already loaded continue working, however anything that involves disk activity hangs. Today I had a console open when it occurred, and I got these results:
- dmesg yields a Bus Error
- hdparm --verbose /dev/sda gives this (I took a picture of the screen and transcribe it here...):

/de/sda
outgoing cdb: 85 08 2e 00 00 00 00 00 00 00 00 00 00 40 ec 00
SG_IO: ATA_16 status=0x0, host_status=0x4, driver_status=0x0
SG_IO: bad response (not CHECK_CONDITION)
outgoing cdb: 85 08 2e 00 00 00 00 00 00 00 00 00 00 40 a1 00
SG_IO: ATA_16 status=0x0, host_status=0x4, driver_status=0x0
SG_IO: bad response (not CHECK_CONDITION)
 HDIO_DRIVE_CMD(identify) failed: Invalid exchange
 IO_support = 0 (default)
 readonly = 0 (off)
 readahead = 6144 (on)
 geometry = 19457/255/63, sectors = 312581808, start = 0

Note that these problems also occured with Jaunty, but less frequently it seems. Please tell me how I can help debugging it.