Half dead hard drive (Seagate ST3500320AS)

Hello there!

(Vista Ultimate x86, up-to-date)

Recently I've been having some issues with my ST3500320AS Seagate drive (0.5 TB, 7200rpm, 32mb buffer).

So here's the story:
I turned on my pc, a BSoD came up just before the logon screen saying something about page fault in non-paged area. It went completely stuck, so there goes a forced restart.
Then, when I was past the logon screen, I was surprised to see that my hard drive (mentioned before) is... corrupted? Windows said: "You need to format the disk before you can use it. Do you want to format it?"
Of course I chose no, because I just happened to have about 400 gigs of important material on that drive. The drive was inaccessible in any way at that time. Two days later, I had some logon issues again, but the drive was somehow back and working. The problem actually fixed itself without me doing anything that has anything to do with it.
So I watched a movie that was on that drive, everything was ok until suddently it stopped responding and I couldn't read any of the files on the drive (the system was okay, I just couldn't access that certain drive - the OS is on a different drive).

I logged out then logged back in, the drive seemed to be ok - but just, just, seemed. The read times were extremely slow. Movies couldn't play smoothly for over 3 seconds. So there is something wrong with that drive, but I just have no idea what, and more importantly, how can I solve this problem. And most importantly, I hope the risk for the drive falling apart completely are very minor - because I need what's on it. Though so far it all seems to be there.

I happen to have 2 of these drives (ST3500320AS). So I used HD Tune Pro to check what's up with my stupid drive (other one is working ok.) Both have about the same percentage of free space (pretty low I should point out.) The 2nd drive is working great and I didn't have any issues with it so far.

The result for read times for #1 drive:

http://www.freeimagehosting.net/im [...] 6eb925.jpg

The result for read times for #2 drive:

http://www.freeimagehosting.net/im [...] 777792.jpg

So there you go... kind of a big difference as you can see. Access the time seems to be pretty identical. Read time on the slow/dead drive is a whopping avg. 0.3mb/s, and on the ok drive is avg. 83.9 mb/s. I don't know if 83.9 is considered to be especially high, but it sure is ALOT faster than 0.3 (Well, to be a little bit more accurate: (83.9)/(0.3)=279.667). So there you go, the other drive is 279.667 times faster than the s**itty one (and as I said before, they're basically the same model, with about the same percentage of free space).

Even running the test on the drive was barely impossible, due to it being so slow and unresponsive. And of course, that is in contrast to my other ST3500320AS, which seems to be pretty fast and highly responsive.

I haven't checked the write benchmarks yet because I care more about the read benchmarks right now. If you think they're relevant please say so, and I'll post the results.

I should also point out that this drive which is half dead was working just fine until that "incident" that happened to me a few days ago (in which my OS "thought" this drive was actually just added to my system and that it is new.)

So what the hell went wrong here? What's up with those ridiculous read times?

Thanks in advanced,
hope you can enlighten me .