VB RegCreateKeyEx failures

Scenario:
Windows NT 4, VB 6.
User has access to Regedit and has no problems adding or modifying items to HKLM entries within registry.
VB code using Windows API (following ALL examples) returns a result of 5 (ERROR_CANT_WRITE?) for this user butworks for others! So far Nobody has been able to explain this or provide an answer (microsoft bug?). Can you?