I am running Ubuntu 9.04 as my host (yeah, I known, but this suits
me fine). I just upgraded my laptop from 3GB to 4GB, Looking at
the Settings on booting up, I see 4096 MB. So that is fine.

I am running Oracle VirtualBox as a VM Manager and Windows 2000
Pro under that as a client. I went to check my Systems settings,
and VirtualBox still reports 3072 MB as its cap. I don't know
how to check or resize the RAM available under Ubuntu. And I
don't know if there is a special case of getting VirtualBox to
recognize it if it is changed.

With 4GB of RAM, I can better balance memory needs for the host
and for the client. So I would like to solve this problem.
Any ideas?