In general this type of error is due to the Bios not being ACPI compliant. Again, in general, it means you should look for a Bios upgrade: http://www.fica.com/techsupport/bios_and_drivers/bios_and_drivers.stm .
In particular, the (0x70) error is a timing question where the RTC (real time clock) is generating a memory address for its calculation of perhaps date, time (or possibly clock speed) in a memory register that usually is owned by Com1:
 
You don't say why or when this error occurs. I notice that you have it overclocked. If it just started happening and it had been running fine previously, look to better cooling.
 
If it is happening within a game, the game wants to access perhaps the Com1 port and slams into the memory address being used by your real time clock.
 
More specifics would be helpful. So many of these Stop errors are undecipherable without a debugger to track down the exact code line error.

even with the system overclocked or running stock i get this error, sometimes it causes a hard lock and other times it doesn't, just to set the records straight, i don't even get a BSOD, just locks up.

When did it first start happening? Can you tie its first appearance to new software or new hardware? By the way, did you see if you have the most recent bios?

I get exactly the same error in the event viewer except in my case the descroption says:
"AMLI: ACPI BIOS is attempting to read from an illegal IO Port address (0xcfc), which lies in the 0xcf8 - 0xcff protected address range. ..."
 
The rest is the same, as you can see it's identical except the IO port address is different.
 
In my case there is no stability issues with this error, I don't even notice it when it happens, but it seems to be in the event viewer about 2 or 3 times every day.
 
I've updated my BIOS to the newest vesion and I have yet to get the error since I did that, which was about 2 hours ago. I'll let you know if this has changed anything.
 
Oh, by any chance are you running a VIA chipset? I am, and I suspect it is directly the problem.
 
Also, looking back, I see the errors go back to the day I installed WindowsXP, and I know with out a doubt that Win2k had no problems with ACPI on this machine with the old BIOS.

Reset the Bios to default settings then Try disabling all ports that arent being used. Like seriel, printer and what not.

I see from the FIC site that your mobo is a KT133a chipset board, so is mine, and I now know that the newest BIOS from my manufacturer did eliminate the problem for me. I see that FIC's newest BIOS version is called VDC49, is that the version you have? If you don't I'd suggest up[censored] it, it's fairly new, and even though not explicitly listed in the changes, improved ACPI implimantation may be part of the update. This seems to be the case with mine.
 
Obviously I'm no expert here, but just someone relaying what worked for me in the same situation.
 
Good luck.

Here's the MS Technet article for this issue:
 
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q283649
 
Basically, MS changed added a few restrictions to ACPI in Windows XP (to improve stability), and some older BIOSes do not conform to those. This probably won't cause any major problems, and should be fixed by a BIOS upgrade (worked for me ).
 
[]s Badaro

Does anybody know where you can get hold of a debugger mentioned in Sampson's post, you can read the error messages?
 
FYI
TEL