Update - I've just disabled ALL plug-ins and now it is not showing twice ... I do not have any additional plug-ins installed on this install other than what came with the download.

I guess what I'll do is go in one-by-one and enable to find the issue and report back asap.

Ok, well unfortunately it was the Google API weather widget .... it is running fine on my other test site but for some reason is screwing up the Dashboard on this other one. 

Any ideas?

Update 2

Completely deleted the weather file and re-installed - no go - still showing page twice and the second page is offset  ):