Found the solution: As it turns out it appears it had something to do with the Adobe AIR version, which had been modified by another small app I downloaded unrelated to Poser.

In case anyone runs into this problem, uninstall AIR using the Adobe-provided uninstaller, reinstall from the version that came with the original Poser Pro installer. Make sure you also get rid off the com.SmithMicro.plist files inside your User/Library/Preferences/  which will be rebuilt the next time you start up Poser Pro. Somehow it appears it affects the export. After this the export went flawless.

Sent bug notice to Smith Micro and how I solve it. It only took 9 hours to figure out. 

Have a nice 2011. 

First and last post ever. Back to "stealth mode" and never open my yap again. God forbid.