Error 0146 and Vista Startup Repair

The inspiron 1501 I am currently working with will only boot to the diagnostic partition and startup repair, startup repair says there is no problem and to remove any usb devices and reboot the computer, but there are no usb devices attached.  After many frustrating hours of chkdsk /f, chkdsk /r windows repair from an OEM CD etc. it still wouldn't work.  so I tried the dell factory image restore, i get an empty error box with no message., when using the dell diagnostics i get error 0146 on the drive self test, which of course means the HDD is going bad.....ONLY ITS NOT.  its a fairly new hard drive that when hooked up to my pc works flawlessly, I can browse the file system and backup anything i need, write to and from the disk, perform error checks etc etc, I even scanned it with AVG ( came up clean), but still i only get startup repair when i put it in the laptop,  and I can't run a fresh install off the dvd because it won't recognize the HDD, but its not the motherboard either it passes all system diagnostic tests and boots fine to the XP partition on the same HDD (normally a failing HDD giving this error code will BSOD on Xp boot)

ANY ideas however absurd are welcome