Sorry about necro post, but I had this problem with facial hair and Enb preset, and i got solution
bAllow30Shaders=0 - If set to 1, this option will allow (but not force) the use of Shader Model 3.0 on graphics cards which support it, namely Nvidia GeForce 6600 or newer, or ATI X1000 series or newer. This can potentially improve performance when using HDR rendering for example. However to force the actual use of 3.0 Shaders after making the above change, you will also need to check your RenderInfo.txt file, found under the same directory as your .ini files, and near the bottom the file check which shader package it uses (e.g. Shader Package : 13).
Then go to the \\Program Files\Bethesda Softworks\Fallout 3\Data\Shaders\ folder and rename that particular package to something else (e.g. rename shaderpackage013.sdp to shaderpackage013._bak. Now copy shaderpackage019.sdp and paste it back into the same directory, and rename this new copy to the package name your card uses (e.g. rename it to shaderpackage013.sdp in this example). This will supposedly force Fallout 3 to use the Shader Model 3.0 shaders in the game. In practice this doesn't appear to noticeably alter image quality or performance, so at best it might be used for troubleshooting purposes (Fallout.ini).
taken from here http://www.tweakguides.com/Fallout3_9.html
very simple, no need to change game assets, works for me. Hope this will help somebody