Make sure that dma is still enabled when 2.6 was installed, assuming you installed it from the second disk, and did not compile it yourself.
You should see something like this
Code:
root@slacker:/home/slackuser/thunderbird# hdparm /dev/hda
/dev/hda:
multcount = 8 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 2482/255/63, sectors = 39876480, start = 0
root@slacker:/home/slackuser/thunderbird#