I just purchased a new Dimension 2400.  I installed my Sony DRU-500a 4x DVD-/+RW into my new Dell system.  In my old system, the drive performed flawlessly.  It burned at 4x on 4x media without a problem.  Read speeds were somewhat slow, about 3x, but okay.  After installing it into my new system, the drive will not burn faster than 1x (even though 4x is selected).  Yes, I am using 4x media (the same as I was using with my old system).  Also, the read speed never gets higher than 1.4x, which is ridiculous.  As per the Dell instructions, I changed the jumpers on the drive to "Cable select" before installing.  Any ideas on why this drive is performing so poorly in this new system?