TImeout on Message Box not working

I have a prompt for my users with the code below that displays a message and times out after 3 minutes. It works fine if the box is not touched but if the user clicks the X on the message box and it reappears it just sits there and never times out.

We noticed some users when the box pops up they just try to close it the first time and then just let it sit there.

Show-InstallationPrompt -Message 'CTS needs to upgrade your version of Adobe Flash. This install should take less than 2 mintues. Please save all your work and click continue.' -buttonrighttext 'Continue' -timeout 180 -exitontimeout $false

The countdown time on the program closure on the next prompt works fine when you hit X the countdown timer keeps rolling no matter how many times you hit X.

We like to have a nice welcome message before the browser closure and installation to inform the users. Is there a command I am missing or can work around this?

I use this for an office upgrade…
Show-InstallationPrompt -title ‘Uninstall office’ -Message “This PC is beginning the process of uninstalling the current version of office and installing Office 2013.
Please save any documents. This process will begin in five minutes.
By clicking the ok button, this process will begin immediately” -icon Information -buttonRighttext ‘OK’ -Timeout 300 -ExitOnTimeout $false