i installed a dvd burner in a friends dell computer. he already had a dvd rom and i was just going to add this one in the empty bay. it was a nec nd 3550 a. i could copy pictures and programs from a burned dvd fine, but if i played music or dvd videos it would be jittery. this is the third one i have installed and have not had a problem until now. i have tried cleaning the laserlense with a cleaning dvd, adjusting every setting i could on the drive properties, setting the switches for slave, master, and cable select. the drive that was already in there was set on cable select. is there something you have to do to set the system up for slave and master instead of cable select? also i don't know how to go to the drive properties and slow the read speed down. any help will be greatly appreciated.