Well I think this thread has diverged into two separate problems; The original post being about batch exports where the resulting files all got the same timecode of the first file in the batch, and that’s what was fixed in 6.5.30 based on the release notes; then your issue where the timecode of any export seems to not be quite right in other apps, which probably is not a bug of Nuendo based on the nature of Broadcast WAVs as I pointed out above (but could be a bug if it’s actually writing the wrong ‘samples since midnight’ value to begin with.)
For what it’s worth, if you would like to look at some of your files in Windows with my little app, download it from http://clients.idolum.com/get/d432f71253eb and then run it from a Command Prompt, like:
assuming you throw the EXE on the root of your C: drive; tweak as appropriate.
Now, having said all that, I just exported a little test file from Cubase 7.5.30 at 01:00:00:00 at 23.98fps; Both Cubase and Nuendo 6.0.7 demo (all I’ve got at home) will show the same Origin Time as my app does, depending on how I set the project frame rate in Cubase. So even though I wrote the iXML in the export, which shows the rate correctly as 24000/1001, Cubase/Nuendo don’t seem to actually pay attention to it and assumes the frame rate of all your files is the frame rate of your project.