[ubuntu-in] Gutsy 64 bit troubles.

[Prateek Sharma]

Hi folks,
 I  managed to install Gutsy AMD64 on my acer aspire 5000 laptop. I
have 256 MB RAM, out of which 32 MB is reserved as graphics memory.
However, the kernel only 'detects' 150 MB main memory.(according to
'free'). My system naturally runs real sluggish due to this. Where did
the ~70 MB go?
I ran memtest86, it showed no problems.
This _is_ a kernel problem, right? Anyone having a similar experience?