Software Deployment

Hi. I think i might have a stupid question ([:)]) but here goes..

Today i've created my very own, first package with a GUI. That is, it's an update, and it should show people a GUI stating they should close the program it's gonna patch before the update proceeds. People need to check a box stating they DID close the program. This is my first MSI where I want people to see something is being installed and the first one that interacts with people. (checkboxes etc.)

Now my main question, how do i deploy this standard MSI using sms.. Normally i would use:

msiexec.exe /i "packagename.msi" (switches) /qb or /qns

But this time, i want people to actually see the GUI.. So common sence tells me the commandline should be:
msiexec.exe /i "packagename.msi"

But.. My MSI seems to have trouble arriving at target workstations. [:(] Is there a "trick" or something..? Maybe I need to set SMS to cache the MSI locally? (usually don't do that) Or do i need to check the "Allow users to interact with the program" option in SMS..? In SMS, the package run mode is set to "Normal", so it doesn't run hidden. There's also a "Run: Maximised" option. Maybe that's the problem? What to do..? TIA