I couldn't find any relevant discussion regarding this issue. I'm currently running DF Pro 9.0 (Beta 4). It's a triple monitor setup using Nvidia Surround. The start button menu will only open on the left monitor regardless of which start button I press in all 3 monitors. Also something I noticed whenever I right click on the right or left monitor task bars I get the DF menu but right clicking on the middle monitor task bar gives me the default Windows task bar options. I've also found any changes I make to the task bar using DF doesn't apply to the middle task bar. weird stuff!

*2 hours later*

I tinkered around with it enough I think I figured it all out.