GridControl scrolling is inverted if the mouse wheel's "One screen at a time" option is selected

I'm afraid that didn't work.
Trying to find some more details about his machine that may elucidate the matter.
As I mentioned, he doesn't have a special mouse, his monitor does not support touch input and he only has a standard mouse and keyboard connected.
Any other ideas?

Hi Oliver,
Have all of your users who face this issue upgraded their PCs to Windows 10? By default, touch-pad scrolling is inverted in Windows 10 (it works in "touch-display" mode).

I'm afraid the user is running Windows 7 64bit. Doesn't seem to be an OS issue he can still run the last release of our app using the v14 devexpress libs and scrolling works as expected.

Hello,
We have introduced a certain number of changes into our code between versions 14 and 15, but at first glance none of them can lead to such a problem. Would you please clarify a few points to allow us to continue our research?

1. In what version (including hotfixes) doesn't the problem occur?
2. In what version have you faced the problem?
   If you are using not the latest minor version of v14.2, please try creating a simple example that uses the 14.2.10 version and test it on the problematic machine.
   This information will help me determine the exact minor version where the problem appeared. Thus we would narrow down our search and finally find the cause of the problem.

Please try also setting the TableView.AllowPerPixelScrolling property to false and let us know if it helps.

Thanks,
Andrey

Hi, thanks for your reply.
The problem does NOT occur on 14.1.4.14170
The problem does occur on the following:
- 14.2.10.0
- 15.1.6.0
Changing AllowPerPixelScrolling to false does not fix the problem I'm afraid.
Had another look at their machine - couldn't find any suspicious software / hardware installed. Even tried plugging in a different mouse but still had same problem. Here is some addition info for the users machine:
OS Name:                   Microsoft Windows 7 Ultimate
OS Version:                6.1.7601 Service Pack 1 Build 7601
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Member Workstation
OS Build Type:             Multiprocessor Free
Original Install Date:     07/05/2010, 11:06:34
System Boot Time:          12/10/2015, 15:54:39
System Manufacturer:       Hewlett-Packard
System Model:              HP Z400 Workstation
System Type:               x64-based PC
Processor(s):              1 Processor(s) Installed. [01]: Intel64 Family 6 Model 26 Stepping 5 GenuineIntel ~1569 Mhz
BIOS Version:              Hewlett-Packard 786G3 v02.08, 10/11/2009
System Locale:             en-gb;English (United Kingdom)
Input Locale:              en-gb;English (United Kingdom)
Time Zone:                 (UTC) Dublin, Edinburgh, Lisbon, London
Total Physical Memory:     6,127 MB
Available Physical Memory: 2,776 MB
Virtual Memory: Max Size:  12,253 MB
Virtual Memory: Available: 8,534 MB
Virtual Memory: In Use:    3,719 MB

A period between 14.1.4 and 14.2.10 is very long. Let's shrink it. Try the 14.1.11 version, and if the problem persists here, try also the 14.1.8 version. I am trying to find the exact minor where the problem appeared.

Thanks for your cooperation.

Andrey

We have other thoughts.

1. Please try setting the DataViewBase.WheelScrollLines property to "3" for your every view (including CardView, TreeListView, and TableView).

2. Open the next Windows setting on the problematic machine: Control Panel - Mouse - Wheel settings and check if the "One screen at a time" option is selected.

I am looking forward to your response.

Thanks,
Andrey

I'll try out your suggestion. Just to let you know I've tried the following versions so far:
15.1.6.0
14.2.10
14.2.6
14.2.4
14.1.9
14.1.6
so far all are broken on the users machine

Setting WheelScrollLines='3' in the v15 seems to fix the issue