I ran into issue with another Dell system. The only cure was replacing the drive. Yes, it did what you mentioned, but I found no s/w or h/w reason that corrected it. I can only surmise the drive itself was peculiar and never happened again with the replacement. Though, for awhile i figured the kybd. was actively had a "hot key" that did this by touching it but of course, it shouldn't happening as I reverted all basic or std. defaults. On yet another system, this also happened again because of mny Dell experience it went away after replacing the drive and it needn't be a new drive just a different one.

http://www.google.com/search?rlz=1C1_____enUS373US374&sourceid=chrome&ie=UTF-8&q=random+DVD+door+opening

It maybe the power issue that effects weak electronics on drives, its just omni-ready. Also, the micro sw. could be less than prefect and needs only a juggle to become active. That are also dust clogs at the sw. or seal, never 100% closed. In effect the result of wear&tear on an older drive.

tada -----Willy Happy