Application crashes on starting from one path but works from another path

Question

We have an odd problem.  A small application is deployed to a handful of users. The PB11.5 version has been running successfully for years on XP and then a year on Win7. It was recently migrated to PB12.5 and redeployed. It is a simple deployment - EXE, PBD and runtime DLLs all in the same folder. For one user, the application crashes before it has hardly started.  The Windows messsage "Application has stopped working" is displayed.  The further details shows it is event APPCRASH and module PBVM125.dll where the failure occurs.
However, if the folder name it is deployed to is renamed - no other changes, just a rename - it works fine.  Rename the folder back to the original name and it fails again.
Other than the zero change migration to PB12.5, the application has not changed for 4-5 years and much of it is over 10 years old. While the error handling could be improved, it has functioned perfectly OK in previous incarnations and this version runs properly elsewhere.
Any ideas what might be causing this?
The application is very basic in its design - it doesn't specifically reference the Registry (although the runtime dlls might). My suspicions are a corruption in the Registry or Prefetch or Folder Redirection.
The user machines are supplied under a third party contract so we are limited in what we can see and do to investigate.

Answer 1

Our infrastructure vendor has removed the problem by performing a profile reset on the affected user account.  The application now runs successfully in the intended location.
Presumbably this action has cleared both the User registry and Windows user account settings.  I consider this to be a sledgehammer solution as the user has lost other setting too (eg. Outlook accounts).
I suspect that this is all I will ever know of the cause.  If I learn anything more precise I will share it with you.
By all means continue to offer your suggestions.  However, as the problem has been eradicated, no further investigation will be possible unless it recurs.
Cheers,
Ian