If you have tried saving a Visio 2010 drawing as a web page and then displaying it in a Page Viewer web part in SharePoint then you will know that by default hyperlinks in the drawing will no longer work.
I suspect that this didn't receive much attention during testing by Microsoft as the assumption could be that if you are using Visio 2010 you will also be using SharePoint 2010 and Visio Services to display your Visio drawings in the browser.
There is a way to work around this by changing the output format of Visio to VML (Vector Markup Language) instead of XAML. Unless you choose VML the first time you save as a web page then Visio remebers the XAML default and there is no setting in Visio (that I can find!) that allows you to change this default. The only option left is to crack open the registry and go searching for the relevant setting.
Open regedit and go to - HKEY_CURRENT_USER -> Software -> Microsoft -> Office -> 14.0 -> Visio -> Solution -> SaveAsWeb -> Settings then change "priformat" from XAML to VML
Save your Visio drawing as a web page again and this time it will be produced using the VML format which does not include the xaml_1.js file that causes the error and prevents links from working.
When you add the link to a Page Viewer you should now have working links.