Ok now i'm still troubleshooting. As mentionned earlier, i uninstalled my secondary channel because both devices (DVD-ROM and ZIP Drive) were in PIO MODE and i couldn't change it. Now after doing so i rebooted Windows, and it detected new components (Secondary channel, Zip and DVD) as it's suppose to do. I looked in device manager : my Zip drive is still in PIO mode, but my DVD-ROM is now in ULTRA-DMA (2) mode. I thought that everything was fine now, but since i did that, whenever i put a cd or dvd in the drive my computer freezes, and i have to reset the computer (the ZIP drive works fine though...) I verified and i have the most recent chipset update for my motherboard (Gigabyte GA-81865GME-775)... and my CD burner has the most recent firmware too.
I switched the DVD-ROM Drive back to PIO mode and now it works fine (but slow)...
Now i'm going to change the IDE cable and see what it does, and then if it doesn't work, i guess i'm going to have to suspect the DVD drive itself... unless someone here can give me other ideas?
You help is much appreciated.