laptop is not hibernating

Hi On I1525, when I click on hibernate, it comes up with a black screen for couple of seconds and I listen some type of noise from the side of the computer and I m not sure from where it is coming..it's some scratchy sound either from optical drive or from hard drive itself and the screen resumes to the log on where I need to type my password...it happened once with the shut down option also and I have changed the settings in power options...flashed the new BIOS and updated the Videodriver also..and Created the dword valu in registry also and it worked for two days and I was able to hibernate the system sevral time but on the third day it came back with the same problem...so what I thought that everything works perfectly allright on the computer so it acnnot be the hardware issue and reset the whole computer to it's factory settings and looking forward that it should resolve the issue...and please make a note that all I have done with a very nice dell Rep over the phone and he told that it should take care of the issue but he also told that in case the issue is not fixed they can escalate the case to the higher tech support to their escalation department but I am worried why this is issue is not fixed...In case somebody else had the asme issue..Please help me out so that I can try that resolution on my Own...

I am a Happy Dell customer and I love my Laptop....PLease Help

Onkee