XFX 5770 Hangs while mining for "Long Poll Exception"

[Electricbees]

I have an XFX 5770 which, after mining stable for a few hours, will hang, and eventually cause a shutdown of my system. (Via BSOD)
I'm not sure if it's GUIminer, or the hardware that is causing this, but the system will display "Long Poll Exception" in the gui,
and the card will halt.

Other cards in the system (6950, 5830) will not do this, ever. Just the 5770.
Anyone have any insight on this?

Running;
Windows7-64
Guiminer, poclbm, july release.

Thanks,

Bees

[ForceField]

XFX makes several models of the 5770. You should specify if you're using a dual slot model, as they have an unusually high failure rate.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150501
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150447
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150464

[Electricbees]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150462
This is the one I have.
It's not that the card necessarily is broken, I believe. It runs fine, sometimes for hours, sometimes for days, but always inevitably just stops hashing in GUI miner
while the remaining cards continue to work.
Temps are fine when this occurs, usually around 58-63 degrees. Card is the only card on 1x-16x pci-e extender cable. It is also fed by a separate PSU, (600 watt, card and hdd are the only load on the psu)

[NetworkerZ]

What are the clockings? I have an XFX 5770 too, which is "special" (think it's the same to yours!). It only works with at least 600 Mhz GDDR clocks. Everything below will cause an error (within 1 hour to one week).

Greetz
NetworkerZ

[Electricbees]

I keep it at stock, which is 850MHz, I believe... I've found it to be MORE stable at higher overclocks, as it crashes usually within a few hours at stock, but when I could run it hard, say, 960MHz over break in the cold room, it would keep kicking for up to two days.
The thing runs hot, I bought it used. It's just mind boggling that the card works fine, even for gaming, but stops mining on it's own accord.

[NetworkerZ]

Perhaps it's getting too hot with stock clocks! Try to lower voltage first to get down the temp. And second, lower the GDDR clocks to 300 (or 600) to lower comsumption and heat! Perhaps it helps.

Greetz
NetworkerZ

[Electricbees]

Perhaps it's getting too hot with stock clocks! Try to lower voltage first to get down the temp. And second, lower the GDDR clocks to 300 (or 600) to lower comsumption and heat! Perhaps it helps.

Greetz
NetworkerZ

Trying this now. Lowered clocks, and voltages, temps are under 70c right now. Memory is at 300. Seems to be doing fine. Will report back with details.