Hi,
Can you tell me a few other details:
1) In the "Adjust Capture Times" dialog, do you have the box checked for "Update file IPTC/XMP for date/time"?
2) In the Preferences / Files tab, do you have the "Save/load tag and color class in IPTC/XMP" set to anything besides "Never"?
It sounds like the issue is that we are not just adjusting capture times, but updating the IPTC/XMP. If your IPTC/XMP preferences are set to embed IPTC/XMP into TIFF-based RAW formats (which NEF is) then we have to relocate the TIFF table. Some software is not able to handle this type of update to the files and so it fails. I'm surprised that Capture would have this problem, but other software has been known to have problems with this logical type of update. That is why we added the ability to revert. Maybe you have the same issue with editing the IPTC for the NEF files?
If you don't need IPTC/XMP embedded into NEF files and can live with an XMP sidecar file, then you can uncheck the options in the IPTC/XMP preferences to embed IPTC and XMP, which will force an XMP sidecar. Unfortunately, not all software understands XMP so this may limit the readability of your meta data in other apps.
Please send me a private message and I can send you an FTP upload address where you can send me one of the files prior to modification. I'd also like to know what your IPTC/XMP preferences are set to, and the settings in the Adjust Capture Times dialog. You could upload screenshots of the various Preferences panes if you'd like.
Hope that helps...
--dennis