Maybe the balance was tipped on powersupply when adding that device.
I assume jumper settings are correct on ALL the ide devices. Some harddives have jumper settings for: master, slave, or master-alone, or master + slave.
Please give more info on exactly what is connected on the ide channels
what is on ide channel 1 and 0? And what are the jumper setting options and what jumpers do you currently have shorted out on each device.
I find its better to have all cd/dvd devices on one ide channel and harddrives on another. Sometime you will run into problems mixing dvd/cd and harddrives on the same ide channel
What processor is on that k7 board?
cheers