General :: Report Does Not Open In Preview Mode On Some Machines

I have a button on my form that should open a report in Preview node.

On SOME users machines, it appears that absolutely NOTHING happens when the user clicks the button. (preview mode)

Report parameters that may have some bearing are as follows. (Default settings in most cases)
Default View : Report View
Allow Report View: Yes
Allow Layout View: Yes
Auto Center : Yes
Auto Resize: Yes
Fit to page: Yes

Pop_up: Yes (This is NOT the default setting, as I would prefer the report to pop-up. If the report does not open in pop up mode, the users tend to close the DB instead of just the report.)

On the user machines where the problem exists, I have turned off the pop-up blocker in their web browser. It seems to work when opening in Report View.

Button Macro parameters are:
Report Name: My_Rpt_Name
View : Print Preview
Filter Name :
Where Condition :
Window Mode : Normal

Environment
SQL back end (ODBC Connection to server)
Access 2010 Front end

I am developing the DB in the bog standard install with no special permissions / add-ons. Also, my developer (log on) account is as a standard user, so there should be no (network) permission issues.

When troubleshooting on the user machines, If I open the report in design view and then open in Preview mode, it works.

Is the problem with the Form or the Macro or the Preview mode or maybe some Reg key that must be changed to allow reports as pop-ups?