I got your PM, will send you the BIOS this afternoon when I get back home.
It's interesting that you have 100V in half a country and nobody would make decent UPS for that voltage. The UPS you found and pointed out in that thread seems fine though, but you also mentioned you already have an UPS. I just don't know whether you're using it now or not.
No, the bios files are still on the ftp. Check
here.
They just pulled 1017 and further development.
As for the flashing, I always used the windows utility and never had problems. Flashed my bios at least 10 times.
Since you have so many problems with NV SATA, maybe you should try using the Silicon image ports for a while. You have to enable the controller in your bios first though. It's strange though: I also have a 120GB seagate, same model as yours and an additional 320GB WD and have no problems at all. I also used to have a PATA maxtor, but I gave it to my cousin. No problems whatsoever with any config.
If you worry about SI controller being *only* RAID, it is AFAIK not. You can use your drives normally with it, without setting up any RAID (AFAIK). Never tested it though since it's a bit slower than NV one and I absolutely hate the additional POST waiting it's BIOS causes.
BTW: Is the fan on the north bridge (the small one - 4cm) spinning? It failed on my MB once. The NB was fine despite that (for about three weeks until I got a replacement), but I wonder: that might cause some trouble if your NB overheats during periods of intensive load.
Edit:
1) Absolutely try a newer BIOS. If the flashing fails, you will know why you had problems (bad BIOS flash chip)
2) Just added another option: move the drives to SI controller
3) You can always buy a new MB, but I don't think we are sure your MB is even the culprit here which means buying a new one might not even solve the problem
4) If you already own an UPS, don't bother buying a new one
I listed them in order of my preference. These are the steps I would take now to try solve the problem.