My fan has gone crazy, or something

[Apa]

Yeah, as the title reads my fan for my X1950XT has gone crazy (stock). It just randomly starts spinning faster for no reason. The temps are good, I have had Everest ultimate running and I checked temps exactly when the fan started speeding up, and the temps were as they always were, at 48C.
This happens, as said, randomly. Always when I am not doing anythin special, like surfing the net.
What is even more strange is that Rivatuner says the fan is still at 36% (same with ATi tool and tray tools), BUT it says the RPM is constantly switching from between 3000 to 4000.
I can hear how it speeds up and down extremely fast when this happens (I mean, it sounds like it is about to slow down, but ½ a second it's back to w/e % fanspeed it were before going down), and it can only be solved by a reboot.
If I try changing the fan duty in i.e. ATi tool/tray tools or Rivatuner to like 20%, it instead goes to 100%!
Now what is even MORE strange is that if I set the fan at 80% fan duty or more, the fan STOPS!
The only positive thing about this is that the temperature goes down with about 5C, but the sound is unbearable! Not only because the fan is noisy as it is, the flickering from the slowing down and speeding up makes it even more annoying. I can't continue rebooting all the time this happens D: happens too often.
Anyone that have any idea what's going on?? As mentioned it's the stock fan.

I have ATi tray tools set to run at startup, but I get this problem even without ATi tray tools starting with windows.

I will change the fan as soon as I get money (in like 3 weeks D: ), but in the meantime I need some cooling on the card, and I only have the stockfan. D:

Suggestions? Ideas?? Solutions??? Any comment is welcomed :)


EDIT: I have to go to bed so I'll check back tomorrow if anyone have said something!

[Protius]

can't u use att or tray tools to keep the fan spinning at a certain speed?

[Zubasa]

can't u use att or tray tools to keep the fan spinning at a certain speed?
Well you don't want to slow the fan on a X1950XT by too much.

[Apa]

can't u use att or tray tools to keep the fan spinning at a certain speed?

That's just it. If I set the fan at, let's say 30% (when this "problem" come), it instead goes to 70%. If I set it to 40%, it goes to 60%. If I set to 100%, it goes to 0%, and this is with ATi tool, ATi tray tools and Rivatuner.
Now, when this problem have NOT come yet, the fan is working as usual. If I set it to 40% it stays at 40%. In other words, nothing is wrong.
I have never seen anything like this neither can I find anything near this when I look on google o:

Thanks fore the replies.