+2  A: 

I would recommend trying to set an explicit width on the menu items. I noticed in Chrome it is saying that the width of the sub-menu items is around 1600px - which would be why it is pushed so far over.

Also, I feel like I have to say this, I wouldn't recommend using the SolPartMenu for your DotNetNuke navigation. There are much better alternatives out there. You're going to keep having headaches with the SolPartMenu and from my experience its just not worth it.

Ian Robinson
Thanks much. I'll look into a better (more modern) menu.
AndrewCr