system freezes, HD error massages

[sd]

Hi,

if got some problems with my system performance. The system freezes by 
simple tasks (like checking mails) for some seconds and then continues 
working. Additionally I have problems playing one simple stereo track 
(imported audio) in ardour.

I suppose there are problems with my HD (after an error massage in ardour).

In the log file I found something with reconfiguring my HD....

Dec 17 10:01:13 morgenthau kernel: [  576.129020] ata1.00: configured 
for UDMA/100
Dec 17 10:01:13 morgenthau kernel: [  576.286300] ata1.01: configured 
for UDMA/33
Dec 17 10:01:13 morgenthau kernel: [  576.286315] ata1: EH complete

I' m sorry, but I am new ubuntu user.

Greetz,
sd