Player Camera forced up in-game with UDK

[Knowon]

My player camera (first or third person) is always forced upward and then rotates once it's facing up. This occurs whenever I open a level in UDK (whether it's one I created or one of the ones shipped with UDK, whether opening in UDK directly or from the Editor). If I constantly move my mouse down, I can counteract this to a certain extent, but it's a losing battle and it shouldn't be happening anyway. This occurs in both the 32bit and 64bit versions.

I thought it might be my mouse, but I've got the most up-to-date mouse drivers for my Microsoft SideWinder X5 USB Mouse (I've also tried with a different Microsoft mouse, but I don't have another brand mouse to try [all my Logitechs keep on breaking, and I've finally given up on them]). I loaded UDK with the mouse disconnected, and then with my keyboard disconnected, and neither had an effect. I've also force-closed the Microsoft Mouse software running in the background with no success. In fact, I've closed all background programs I know I can safely close, and the issue still occurs.

I've uninstalled and reinstalled UDK. I've found this problem to occur in the current UDK Beta (UDKInstall-2012-03-BETA), and even in a previously installed older versions of UDK (UDKInstall-2011-04-BETA) that was working fine previously (never uninstalled). This would indicate to me an issue that might not actually be due to the UDK, but something else. I'm just don't know what it would be. I was hoping someone else might have an idea.

I apologize is this has been posted elsewhere, but I really have searched for this issue/solution without luck.

Thanks in advance.


PC Specs:
OS: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.120305-1505) [English]
CPU: Intel Core 2 Quad Q6600 @ 2.40GHz
RAM: DDR2 1066 4096MB
GPU: ATI Radeon HD 4850 512MB (DirectX 11) DriverVersion: 8.17.10.1124 [Most recent drivers]

[Graylord]

If you have a gamepad connected, disconnect it.

[Knowon]

Haha! That's it! My idiocy knows no bounds.

I was just about to post a response that I didn't have any gamepads connected (I pretty much never do), when I realized I had accidentally plugged one in while I was moving my computer a few weeks ago, and it had fallen behind my tower!

Thanks for the quick and helpful response!

[Graylord]

No worries, it's surprisingly common.