I have a DVD-Writer in my A105-S4334 Toshiba that has always been identified by the system as a Matshita UJ-841s. I have been having issues with it and removed it to remount it. The label on the chassis is UJ-850 Hw 1.00 FW 1.60. I need to replace the drive. (It won't read any data CD -even ones it has burned) I assume I should buy the UJ-850 regardless of what the system is identifying it as?? Am I correct?? And, could someone tell me why it is misidentified?