Fixed in WWMT 1.772
The orientation of models in the QC Generator has been flipped on the Z-axis and the VMF Exporter is also rotated to accomodate this result. You may need to recompile models compiled before the 1.772 update.
Do not use bitmap filetypes that Max doesn't know how to read.
Using unknown bitmap types on world geometry and displacements will crash the VMF Exporter. This currently happens if using VTFs in materials in 3ds Max 2013 since there is no VTF plugin yet.
Bringing life to your scenes
Detailer is a detail sprite primitive plugin with exporters. The tools allow you to either create VBSP files, and will also create geometry that exports into the Source Game Engine with the Wall Worm VMF exporter.
Fixed in VMF Exporter 1.21 (WWMT 1.768)
The current VMF Exporter does not yet export the correct texture alignment, rotation and scaling on brush geometry and displacements.