And...now it smells funny....like its hot...maybe something burned up in it?!
This is not a good sign.
Ultra DMA 5 on an optical drive? Usually you see that on modern hard drives.
How do you have it set up in the computer? Is the dvd drive the master on the secondary IDE channel? If so, it will be device 0 on that channel, and should probably be Ultra DMA 4 or 2. Might check again just to be sure.
And if worst comes to worst, new dvd drives are getting fairly inexpensive. Pioneer, LG, Plextor and others are making some good drives these days. Look through the dvd drive hardware forums for more info.