[Ubuntu] Ubuntu 32 Bit shows too little memory (only registers 3GB instead of 4GB, 5GB, &GB or worse)

While installing Ubuntu 8.04 i found that it didn't register the 6 GB installed memory I have in my desktop.
BIOS shows 6 GB alright, but Ubuntu only shows 3 GB.

I found that the following solves the problem in Ubuntu

Install linux-headers-server and linux-server packages:

sudo apt-get install linux-headers-server linux-server

Then restart your system...

Now meminfo will show 6 GB:

zyb3r@xyz~$ cat /proc/meminfo
MemTotal:      6087608 kB
...