Thanks pirate, actually before your post I had went back into the converter (Deep Exploration 2.1) and tried checking/unchecking combinations for all the exporting options.
I finally hit the right combination !
In case anyone uses DE, these are the options checkmarked on the .x export General tab (except for Textures, no other tabs used):
Texture Coords
Save materials
Save normals
No Frames (this was the culprit I think, never had it marked)
Turn to Left-hand system
Max points in polygon = 3
Hope this can help someone else, maybe even with a different converter.