Hello,
Assuming that your system and VS installation are stable and not experiencing problems, I recommend trying the following:
1. When you export your setting in the Import and Export Settings wizard, make sure that the All Settings box is checked at the top of the tree view. It could be that some settings got skipped when you last exported.
2. When you save your exported .vssettings file, save it in a different location than the default, or change the name to something unusual so it stands out. Then make sure you're importing that exact file. It could be that you've been inadvertently importing an old copy of the .vssettings file.
Good luck,
- Kemp Brown [MSFT]