Hi,

Everyone I know of who had a WD passport has had issues. I would recommend Lacie, or Seagate.

About power vs buss power for Hard drives. If you need a USB hard drive for Digital Recording, or using softsynths, you will need a fast drive (7,200 rpm). These drives need external power, your buss will not support it. If on the other hand you are using it for storage, or loading RT/RD on BIAB, then a 5,400rpm drive should be fine, and most will work with buss power from your laptop.
I don't recommend the slow 4,200rpm drives, these are really old,big,heavy and do not have a lot of storage anyway.

Another direction you might want to look at is the new Solid State Hard Drives. These don't use a platter, they are much faster than even the fast USB 2 drives, they don't get hot, and from what I've been reading, they are very safe for your data, although I do recall Mac posting that he had heard about some drives failing.
The bad side of this is the Price! These drives are VERY expensive ($2-600) for a 160 or 250GB drive.

Here are a couple of places to look>

www.tigerdirect.com

www.newegg.com

Hope that helps you,
Ed