A PMR is probably the best way to fix your user's issue, as it could be required to review some of the personal information such as the local names.nsf for instance.
I understand you have opened a PMR already, so the best would rather be to request an update to the assigned engineer working with you on this matter.
From a general stand point, you may want to check the actual Notes client version, use the latest Fix Packs available and avoid any pre-gold release the user could have downloaded for test (the Notes 9 client was installed by many power users when it was made available).
Also, it could be interesting to see what happens for the same user on a different Notes installation, so to make the difference between a user-related and a configuration related issue.
I hope this helps