CD-ROM misbehaving in Persario X1000...

I recently got a refubrished Compaq Presario X1050US (the label reads
X1000, so it depends on how you look at it). It's a very nice unit,
except for the CDROM behaviour:

1. Access time is verry long... 20s for original CDs, more for CD-R's.

2. That drive is LOUD... I'm talking about motor noise, including
causing the whole laptop to vibrate while spinning.
(hear for yourselves http://www.sfu.ca/~dlahat/cdrom.mp3)

3. There is a known issue with this drive, of being unable to burn 4X
DVD+RW media. There's a firmware update specifically for that, but it
did not change a thing - I still get "illegal media" when trying to use
these discs.

The actual model is Sony DW-P50A, a 24X DVD+R/W combo.

Since my warranty ends in a week, I'm trying to figure this all out. Do
you think these problems might be connected? Should I send away my
precious laptop for service, and insist on having the drive replaced?
Or perhaps it's just a coincidence?

Thanks,
Drew.