Surely there must be a reason behind this? Is it safe to use firmware that removes rip speed limitation?
Sony have software to increase the rip speed called DSS (drive speed selector) but its not for the dru500a\ax just the 510a as yet.I know this does not answer your question but it shows it can be done by software
here is the link for any 510a ownersDSS (drive speed selector)
Probably they want to make it difficult for people to rip their DVD's to DivX.
It's just to discourage ripping. Which is primarily only done when copying DVD's. I guess they feel that it's necessary to annoy those of us who just want to make backups too.