First make sure all the connections are right, and seated firmly. And another thing is to try it to another system, see if it gets detected there. Else you could RMA the drive.
I tried it in another system(Windows XP), and it worked fine. The drive was working and was being detected normally. I checked, and all my data was on it.
So, I hooked the HDD back to my system and it was being detected normally by my system.
I'm pretty confused, and it could probably happen again. Do you think it's a faulty drive?