FAINT TICK, CLICK NOISE scorpio 500gb

hi everyone, i have a hp g6 laptop, with a WD BLUE SCORPIO sata 500gb harddrive in, brought it new 9 months ago from hp, and basically over the past 4 days my harddrive makes some very quiet/ faint click/tick noises, no whirling, grinding etc, and the click/tick noises are not every spin of the drive, but approx a few times in 2 minutes. i dont think its a failure but still, its enough to have me on my feet :-), i have 6gb ram installed and a fast processor but yet its not really as quick as i thought it would be!. does anybody know if this is a common noise and nothing to worry about??? thanks

Hi, to be sure you can run a test using DLG. 

http://wdc.custhelp.com/app/answers/detail/a_id/940/session/L3RpbWUvMTM1NDQ3MjI5Mi9zaWQvRzM2cXNMY2w%3D

This one should also help. 

http://wdc.custhelp.com/app/answers/detail/a_id/568/session/L3RpbWUvMTM1NDQ3MjI5Mi9zaWQvRzM2cXNMY2w%3D