[1.0.21] Line horizont, fog and skybox causes visual issues

[Vader]

I hope this hasn't already been mentioned, because I'm not sure if this is a real bug or just one of those unfixable issues.
Anyways, the problem is that sectors with fog applied to them, f_sky as a ceiling/flat and a line_horizont line special on one of the outer linesd of the sector, cause some very weird effects.
Here's a screenshot that shows the problem:

[spoiler][/spoiler]

It may also be of importance to mention, that the skybox has also fog applied to it.
For reference just check the current M8 (the corridor east of the blue key) from the server Graf!

Apologizes, if this has already been brought up.

[Graf Zahl]

I have seen this work so:

1. What graphics card do you have?
2. Do you have a demo map or can you tell me what map this is?

[Vader]

1.My Graphics card is a MSI RADEON 9550.
2.The map is the current Z1M8 from the developement server. It's the corridor with the Cacos east of the blue key room!

I have the feeling, that the problem may be in the map itself...

EDit:
Well, after some more tests, I can say that it definitely is not the maps fault!
Additionaly, it seems not to matter if there is a skyboy, normal sky texture or just a standard texture on the sectors ceiling!

[Alter]

I think it's graphics card problem.... never buy MSI Radeons they are worse than Gigabyte radeons!

[Graf Zahl]

ATI + fog = trouble.

Sorry, but since ATI's driver doesn't do what it is supposed to do with fog I can't fix this. On my Geforce all looks correct.

[Alter]

I never had problems on my ATI radeon 9600 card with fog.... even with newest drivers i use to check out my graphics card temperature

[Vader]

Argh, too bad.
Unfortunately i can't afford a different Graphics card atm, besides that it does the job for every other game.
I'll just have to live with it then... thanks anyway!