This is a bit of a leap but - particular parts of Windows can only run once and are not allowed to have multiple instances from different users. I wonder if this is the issue here. I'm thinking particularly of explorer.exe. If this sounds like it might be what's tripping up the RUNAS method, try:
- start a new cmd window as the user by running: runas /noprofile /user:domain\user cmd
- open taskmanager and kill the explorer.exe process (you'll loose your start bar when you do this)
- in the cmd window type: explorer.exe
- The start bar and windows will come back and be running as the other user
Now try your application. When you're done be sure to switch back by:
- open taskmanager (this will be running as the other user)
- Kill the explorer.exe process
- press ctrl alt del and then click task manager (this should make it run as you)
- in taskmanger, click file - new task
- type: explorer.exe
- Everything should now be back to normal.