Small mouse acceleration in some servers

[ZeLf]

Hello. I'm having a problem I'm not sure if I've detected it before in my 15 years playing this game.
Every time I install UT I always do a full test to check if mouse acceleration is completely disabled. Usually the steps are this:

1. Windows mouse 6/11
2. Disable enhanced pointer precision
3. Disable mouse smoothing in-game
4. Enable direct input
5. Disable VSync

When I do these steps I usually go into a single player game and do the following:

1. Fast 90° (more or less) turn
2. Slowly return to original position

It has been working perfectly all these years. The crosshair always goes back to the original point with exactly zero offset on the mousepad.
All good until yesterday that I did this test on a server instead of a single player game and this time there was a slight acceleration. The crosshair was a litle offset from the starting point. Of course I went to a single player game to make sure and for my surprise it didn't happen.
Then I went to different servers and for some of them I had acceleration and for some of them it didn't. In all the servers I had acceleration they had one thing in common, UTPure or NewNet (which has UTPure embedded? I'm not sure).
So last test, I created a clean server and had no acceleration. I put NewNet on it and boom, acceleration appears.

I'm not sure if UTPure is really my problem or I'm missing something. All the configurations remain the same for all tests which are:

1. OpenGL
2. Tried all tests with both 436 and 469b versions
3. FPS around 300 in all tests
4. Used the same video card for all tests
5. Tried all tests with and without MarkC mousefix

[Berserker]

Some server mods actually force different mouse inputs to your client. And yes, I do think NewNet uses its own mouse input. Also you are correct - NewNet has its own modified UTpure inside of it.

I think you should try this pre-configured 469b UT and see if you still face those issues.
--Link removed--

Try not to replace the inis and just change your sensitivity and controls

[ZeLf]

Try not to replace the inis and just change your sensitivity and controls

I did. The results were identical to all previous tests

[UnrealGGecko]

@Berserker please don't share the full version of the game like that, it's still being sold on Steam and GoG by Epic.