7 64bit USB 2.0 External BluRay burner problem

thx mike :)

@ ken9122: hmm... you maybe right, but then again, why does it work when i put plug in the power cable first but not when i plug in both cables simultaneously?

and how come that the small elitebook deals more power over one USB than a large 17" pavilion over 2?

here are the comparison links:
HP EliteBook 2530p Notebook PC specifications - HP Large Enterprise Business products

sorry, but i can't find the HP 9500t cto specs (that is the laptop that i was having problems with)

What I did was get one of those plug in the wall USB chargers. It's got a couple of USB jacks on it that only supply power. They are meant to charge your MP3 player or cell phone without having to have your laptop or PC on. I plug the USB power cable into it and the USB data + power cable into the PC. Solved a lot of similar issues I had with my mini (laptop drive) external case that didn't come with a dedicated power supply. I make it a habit of plugging in the power cable first and waiting a little while before I plug in the data cable. If you do it the other way around windows may try to access the drive right away and weird things happen when there isn't enough power to get things moving at full speed.