texture browser doesnt work :(

[Narf!]

hi there

i tried to make an own custom shader, so i start the texture browser, click new, type in package (map1), group (textures), name (white) and class (rawmaterial), -> shader properties: when i try to click here on the three dots for browsing my tga (fe. for diffuse) nothing happens, it doesnt start the browser like it should,

is this an error? am i doin something wrong?, i cant find any tutorials in the net on creating custom shaders, i have the same "browser doesnt start" problem with importing textures in upaint, maybe it has the same source,

any ideas? help pls