Hi,
Two players of my game reported that sometimes the parts of screen are flickering and it is related to backdrops as well as active objects.
Here is the video:
http://www.zkouknito.cz/video_53858_chmatakov-error

Happens on WinXP and Win7, DirectX 9c. The first one has got NVIDIA GeForce 7000m, the second one will let me know.

It looks to me like what happens when rendering single-buffered with no v-sync. Nothing should be rendering single-buffered any more, because it causes a lot more trouble than it is worth.

Try enabling v-sync.

Maybe your game takes too much memory and their video cards don't like it? A GeForce 7000 is quite old.

PS: did you tell them to check if their drivers are up-to-date?

Yves: yes, they have latest drivers. Thats the problem, if there should be large frame with the whole game world, HWA will be useless when taking too much memory That was why I asked (way before) what about settings like Render area (X,Y to X1,Y1). But I understand its probably too difficult to implement.

I don't see what you mean by "render area", MMF only renders the area that is visible on screen, nothing more. If there is a memory issue, then I don't know why, Direct3D should handle that correctly.

As Dynasoft said, it could be a single-buffer issue. If I remember correctly Direct3D decides itself how many buffers it uses, maybe in certain cases it can choose only one buffer for some reason.

Does your game go to full screen immediately with the "Change resolution" option or do you switch to full screen with Set Full Screen action after the game starts? If you switch to full screen after the video memory is full, then maybe it has not enough free space to allocate the ideal number of buffers.

Just random thoughts...

EDIT: I'll try to free as much memory as I can before switching to full screen, just in case. Try with the next version.

Well I have heard that with HWA everything is rendered, so its OK

The strangest aspect of this issue was that the player who reported it can now run the game 3 times and it works well. There is no fullscreen used at all.
I have just checked v-sync, I will release an update and get feedback from players.

It's also possible a low-end mobile GPU like that just doesn't support double-buffering. I haven't heard of any GPUs that don't, but I suppose it's possible.

Blizna: It would be worth seeing if you can find out if the issue is isolated to those two machines or if all NVIDIA GeForce 7000m GPUs are affected.

EDIT:
According to: http://msdn.microsoft.com/en-us/library/ee416519%28VS.85%29.aspx
and: http://msdn.microsoft.com/en-us/library/ee416646%28VS.85%29.aspx

Direct3D9 doesn't support single-buffering. If you ask for 0 back-buffers, you get 1. This means it can't be anything MMF is doing, and has to be something about the machine or driver.