I use XP. When I insert CD/DVD into any of the drives the system hangs - It seems that system waits for some data from this recently inserted CDs/DVDs, because after about 15~20 seconds everything is ok again - this time is necesary for system to get access to CD/DVD disc. How to turn this 'waiting' off? There is no logical reason why system should stop working for a while when disk is inserted...

Thanks in adv

Here are few things to check.
1.) Try each drive individually as master (with nothing on the slave) just to make sure the hardware is still working properly. Note: Do this only if you are comfortable with H/W)
2.) Consider updating the motherboard drivers, and/or moving the new burner to a different pc temporarily to see if the fault follows it.
3.) Make sure UMDA is disabled for the cdrom drives.
4.) It Could be a Jumper setting problem too. Mean the way these H/W's are connected to the IDE Cables

The only thing was UMDA turned on, but why is it a problem? Wikipedia says: "Computers that have DMA channels can transfer data to and from devices with much less CPU overhead than computers without a DMA channel."

Why DMA hangs computer???

OK, switching to PIO didn't do the trick...
I am open for another ideas.

Disable the AutoRun for both Drives.

Already did :)

OK. The solution:

Do not use "detailed" view in explorer, especialy in "My computer" folder. If you do, after inserting CD/DVD Windows will try to check the information on inserted medium to display it. ... :)

What if you dont open "My Computer" and open just Explorer or any other app? Does the freeze occur?