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Does your "blank" screen open in the same (self) window? If so the "self" is working, for some reason I think I had this issue about a year ago and found that for some reason if the ending "/" was not at the end of the URL it gave you a blank page. "modules/contact/"
Try visiting your "contact" page then copy/paste the exact url into multi menu. Just a thought from past memory, however there is no promise of a good memory these days.
This might and might not help, but it too early and not enough coffee
