Acer Aspire 7738G-904G50Mn partition problem

Hi there,
Just bought an Aspire 7738G-904G50Mn that comes with Vista 32 bit. Installed it, works fine untill i try to create another partition. Recovery by default creates a single partition so i've tried to add another one. So, shrinked C: and successfully created a new partition of a certain size.
So far so good. Rebooted the laptop and surprisingly the newly created partition vanished from My computer. Disk management can see the partition... so i don't see what's wrong. Tried to use third party software, still the same thing. I create a partition, i can access/write on it but on reboot it dissapears. I can also use disc management to delete/re-create partition and i can use that created partition untill the next reboot. Any ideeas what might be the problem? Why does that newly created partition dissapear after reboot?
Thanks in advance.
Cheers.

After 10 hours of hard work i found the solution.
So, from the beginning....as i said in my first post, i've tried to create another partition on my 500GB HDD. Default was 400 and something and i wanted to shrink C: to 100GB and use the rest for a new partition.

What i noticed is that using Windows disk management i can shrink C and create another partition but after the first reboot my newly created partition vanished.

Here's why: if you look at the info in Disk Management there's a hidden partition tagged EISA. After i created a new partition and rebooted, partition vanished and when i looked up DM again i saw that the newly created partition was EISA too which led me to the conclusion that no matter how you try to shrink C: or create another partition either using DM or other software (windows based) the recovery partition converts it automatically to an EISA partition which i said above IT IS HIDDEN. So after shrinking C: and the first reboot windows hides the newly created partition converting it to EISA.

What i did in order to take full advantage of the full capacity of the hard drive.

Firstly, I'VE CREATED THE RECOVERY DISCS (very important if you don't want to lose you genuine operating system) took the hard drive out and connected it to another PC (doesn't matter if on that pc is XP or Vista)....INSTALLED Paragon Partition Manager Professional 9.0 (PQ Magic can be used, Acronis Disk Director, and so on)and erased all the partitions INCLUDING those hidden ones (EISA) i've told you about. Completely deleted everything on the hdd, left it empty and unpartitioned. Then, using the same software i've created 2 new partitions, a 100GB for C: and what remained (so i had 2 partitions), formatted'em NTFS.
Second thing i've done is to disable in BIOS D2d recovery (switched to disable) before starting the new instalation.
Placed the HDD in the notebook and booted it with the first recovery disc.
Everithing works fine now, i have 2 new partitions, can reboot my notebook a hundred times, my partitions remain the same, and can even shrink my partitions without being afraid that something might hide'em or that after the next reboot they'll vanish.
That was the whole thing.
As far as Acer users are concerd about.... you don't have to worry about those recovery partitions, you can erase those, having the recovery discs made, you can restore your genuine windows.
I'm fully aware that there are several other ways of erasing those hidden partitions using a linux live cd or something...

Concernig Acer and this nerve wrecking solutions in order to get you HDD partitioned... i have never seen such an enormous foolish and stupid solution to partition your HDD. Why in the world would Acer want to restrict users to partition their hard drives as they wish ?!
Anyway, maybe there's a much easier solution i didn't find it, dunno.
Hope this post will help.
Cheers.