http://bugs.winehq.org/show_bug.cgi?id=17708
--- Comment #18 from Heiko zuxez@uni.de 2013-02-20 15:13:21 CST --- Meh. Frikkin buggy game. I upped the Graphics to max on 1280x1024 (except for HDR and highres textures; without closing the game), now the characters are rendered correctly, though the shadows are broken. I don't get it. So basically one or the other is weird. Still a shader thing I'd say. Maybe the order of loading/compiling is important? Some storage caps? This is on git 5069ad71b4ce3a0bf8b084842672573837e1a88a. Though older versions don't make a difference.
On a side note: Splinter Cell Chaos Theory worked perfectly. I guess because of the shaders. Double Agent requires SM 3.0. Chaos Theory could optionally use SM 3.0 which worked for me, though they did not contain any shader comments like // CTAB or // PRES.