UBUNTU 9.10, Black Screen after UPDATES

Hi! I am new to ubuntu and linux and I have win7 on my computer. I installed linux 9.10 to another partition. I was using both os with grub. And i had 5 choices in the grub screen:
Ubuntu 9.10 build ....
Ubuntu 9.10 ....(recovery mode)
Mem test...
Mem test...
Windows 7
I installed startupmanager and changed boot default in it, and boot win7 and ubuntu with no prblms.

After that, i changed some boot settings in starupmanager, like resolution and some other stuff i cant remember(that was like a week ago), while doing that I was installing all the updates. it asked me about the grub version, if wanted to change it or keep it, giving 5 choices, i chose "show me my version" to see and than choose, but it just continued installing updates!? Anyway, after that update i rebooted, and saw that grub screen was changed to:
Ubuntu 9.10 build ....
Ubuntu 9.10 build ....(recovery mode)
Ubuntu 9.10 some other build ....
Ubuntu 9.10 some other build....(recovery mode)
Mem test...
Mem test...
Windows 7

i tried booting both builds, neither worked!
I just get a BLACK SCREEN!
But i have no problems with booting Win7.

So, is it about startupmanager, grub, other updates, doing startupmanager and grub thing at the same time, or smthng else?
What can i do about that?
I am pretty new to linux and ubuntu, i have almost no ideas about the console commands right now, just trying to learn and figure out the system, can i do smthng with some commands in the recovery mode? Or other solutions?

THANX FOR UR HELP!

:-)

try to run in "Ubuntu 9.10 build ....(recovery mode) mode". and use command "fsck"
and confirm yes when you asked!