Aspire 1804WSMI Power Problems

I was an happy owner of an 1804WSMI. I got it some six months ago. Everything was working fine then, one day, it started behaving strangely. It doesn't shutdown nor reboot properly. It just stays there on the "Windows is shutting down" for quite some time, 45 minutes, more or less the battery total life (which means, the screen stays on until the battery runs out...). The only way to get the system started again is to take out the battery itself, take the AC plug out, leave it be for a few minutes. This way the internal battery resets and so do the bios settings.
But. There's always one....
Sometimes this procedure doesn't work on first try. At one time i'm able to get to the login screen before the system freezes. Sometimes the primary bios loads and the vga one doesn't, you get the idea. And everytime i get to load the OS, it just takes AGES compared to the few seconds it required before. This is driving me crazy. I basically run only on AC and due to the work i do i got to reboot very often.
It can't go on like this. Any help could be appreciated.

Stats follow:

Bios Version: v 2.90 (had 2.70, problem started, upgraded to 2.90, nothing changed)
Intel 915P Chipset (latest drivers from ATI, could try the Intel ones)
1 GB Dual-Channel DDR
x600 128MB PCI-e with OmegaDrivers 2.6.83 (2.6.87 are known not to work properly)
ST9100823A 100 GB Hard Drive (in correct Mode)
HL-DT ST DVDRAM GMA-4080N (latest firmware)
WiFi and Blueetooth with latest drivers from ATI

note: Same results with my FreeBSD and Kubuntu installations.