I'm no expert for the topic, but i think your post is confusing. You need to provide more information.

- What is the native resolution and aspect ratio of your LCD?
- What is your desktop resolution (as you're using "fullresolution=desktop")?

nasty corruption of graphics (a mix of 4/3 and 16/10 aspects ratios on the same screen)

How can that be? I don't think this can ever happen in DOSBox. Screenshots? I believe DOSBox uses the game's native resolution for shots, so you'll need to create these with the "Print Screen" key or a tool like HyperSnap.

You could try a fixed resolution for fullscreen mode, like "640x480" or "800x600".

I'm using a 1024x768 LCD, with "640x480" as fullscreen resolution, and scaler set to "none". I'm using ddraw output, so the image will be scaled by ddraw anyway. Never noticed any screen distortion.

Same here, never had any form of corruption and my screen's a 16:9 TV. My screen/desktop res is 1280x720 and I've used all of the output methods. With aspect=true I always have a correct image in the right aspect ratio (4:3 with black bars on each side). I use a 7800GT PCIe but have also used a 6600GT AGP in the past, never had corruption with DOSBox .65 then either.

The LCD screen is a 4:3 in native resolution 1400x1050.
Using different resolutions in "fullresolution" setting doesn't remove the problem.
Only using the "output=ddraw" setting the image is OK: everything from "surface" to "opengl" corrupts the screen, when used in conjunction with "aspect=true" and complex scalers as "advinterp3x".
Note that "scaler=none" works perfectly!
I have attached a screenshot showing the problem.

[/code]

Hmmm... This looks like an "effect" (bug?) in the game, not DOSBox, but that's just a guess. Do you see the same effect in UUW2? Could you test this with some other games?

Unless you have a need for a specific scaler, why don't you use the ddraw/no scaler combination for now? I believe this is the perfect combination, as it shifts the workload of scaling from the CPU to the GPU, and the picture quality is quite good IMHO. It might be interesting to further investigate this topic, though. There may be a bug in DOSBox that could be fixed.

Btw, did you upgrade to the latest NVidia drivers? I've used ATI cards exclusively over the last years, so i don't have experience with NVidia, but from what i read in various forums, certain versions of the NVidia drivers often have troubles with specific games or applications.

Verified also in UUW2 and Elder Scrolls:Arena.
I'm using the last drivers from nVidia (94.24).
Anyway, I don't think It's a driver bug because I have DosBox 0.65 installed and I have absolutely no problems in it with the same configuration.
It seems to me that It is a bug in the last DosBox version.
Do you think It should be signalled to the developers or posting here is sufficient?

See the troubleshoot section of the readme.
Especially assure that you use a fresh dosbox.conf and only change
the entries that are present, AND only change them to valid items.

And see if setting SDL_VIDEODRIVER=windib helps if it still occurs.

Thanks!
Setting the environment variable SDL_VIDEODRIVER resolves the problem!
(but I don't understand the different behavior between 0.65 and 0.70 - for example if I set SDL_VIDEODRIVER in 0.65 the savefiles of the games are corrupted)

SDL_VIDEODRIVER is not meant to solve the problem, it's just to force the
usage of a different SDL backend.
Try downgrading the graphics card drivers, check the directx installation,
look through the various settings of the graphics card driver etc.