I've had many instances of the "blank page" over the past few weeks. I've never resent the page, just clicked "Refresh" to reload and have always been led to the page that includes the update. No double posts here.
I'd suggest NOT sending again.
Resending (without refreshing) seems to work just fine *providing* one checks to see if the first attempt did actually post (sometimes it gets through despite the blank page). This would make sense whether you refreshed or not. You can check to see if the post got through by clicking 'pings' at the top of most FR pages.