Based on your issues and what you have done trying to resolve, it is my opinion you will never get your unit to work or work well and consistantly, at least on your mini. If you have another computer you could test it out there just to be sure it even works.
The environment you are looking to take it into would surely do it in ,this is my opinion, based on my experience with this unit. I did get my unit to read but never to write. It was tested on another computer with the same results. Both mini and other computer running XP Home Service Pack 3.
I ended up buying a Sony, which is very sweet, not cheap and comes with a ac brick about the size of a real brick. It works great however and is well built, with aluminum housing.
To get the I/O Magic to work (with a good degree of consistancy), I replaced the supplied cord (I had another cord on hand) and put a small powered usb hub (CyberPower from WalMart $19.97) between the DVD-RW and mini. Even so, it doesn't burn. I'm pretty sure it was shipped defective or became defective in shipping.
BTW. I proved I had no issues with the Nero software, as the Sony unit was supplied with the exact same software. Being I already had the Nero on the mini, I just plugged the Sony in and was able to use the Nero program to burn CD's.
As for what to buy....anything other than what you have seems to be so much better. (Dell are you listening? Hint: I'm willing to bet about 50% of my posts has been on this subject, several threads)
I would like to know if "ANYONE" has had this unit work as supplied. For me work means "READ & WRITE", not just read.