Those messages are probably generated by SMART and you do have to take a look at your HD.
If you have a GUI set up then you could use
Disk Utility (zoom in on SMART status / SMART Data).
From the command line you can use smartctl (as root user):
Code:
smartctl -a /dev/sdX
replace X with the appropriate letter. The output can be long, but possible errors/warnings should be detailed.