Monitor not detected & blank screen only after logout

[jaithehulk]

Ok here goes,
I installed ubuntu 8.10 for the first time in december 2008, then it had detected all my hardware properly i.e. monitor was detected as samtron(which it is) the refresh rate was set properly.I had no problems of blank screens then.
Recently I had to reinstall ubuntu 8.10 from scratch due to some GRUB issues and now after a successful installation my Monitor is detected as unknown and refresh rate= '0' !!!!!
How do i get 8.10 to identify my monitor??
Also i believe this leads to the problem of blank screens only after logout or during shutdowns!!
I hav an intel 845 chipset(compiz disabled)
any solutions?

[jaithehulk]

*bump* pls help