DVD/CD sometimes not recognized when inserted

Greetings,

I have encountered a odd problem since upgrading my older 17 in Mac Book Pro. When I insert a DVD previously burned in the same machine the drive accepts the disk and attempts to read it, then, sometimes the DVD is not recognized after it is inserted.

The DVD spins up, I can hear the reader head doing its thing trying the read the disk, but it does not mount.

Oddly enough, if I then restart the machine, after restart the disk mounts properly. The disk is readable and has no problems after a restart. I have not tried reading a 2nd disk after ejecting the first after restart, so I am not sure if the behavior stays the same.

If I am adding a music CD to my iTunes library, while in iTunes there is no problem reading the CD and the iTunes starts properly upon CD insertion.

Here are the drive properties:

MATSHITADVD-R UJ-85J:

Model: MATSHITADVD-R UJ-85J

Revision: FAV1

Serial Number:

Detachable Drive: No

Protocol: ATAPI

Unit Number: 0

Socket Type: Internal

Low Power Polling: Yes

Power Off: Yes

Firmware Revision: FAV1

Interconnect: ATAPI

Burn Support: Yes (Apple Shipping Drive)

Cache: 2048 KB

Reads DVD: Yes

CD-Write: -R, -RW

DVD-Write: -R, -RW, +R, +R DL, +RW

Write Strategies: CD-TAO, CD-SAO, DVD-DAO

Media: To show the available burn speeds, insert a disc and choose View > Refresh

Has anyone encountered this problem? If so, is there a software or setting fix?

Thank you,

Tim Kern