I work with Word and Visio a bit for incorporating network diagrams into documents. By default, Word will munge dashed lines of a Visio drawing when the drawing is embedded into Word and this is of course highly annoying when you are embedding Visio drawings with dashed lines into Word.
After some searching I found out that this is known behavior because of the way that Visio saves longer lines to save space, but there is a registry hack to fix the problem.
Go into the registry and
Locate, and then click the following registry key:
Visio 2007 - HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Visio\Application
Visio 2003 - HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Visio\Application
On the Edit menu, point to New, and then click DWORD Value. Type MetafileDashLineAsSolid, and then press ENTER.
Make the value of that key 1 instead of 0 (2 is the default behavior, but 1 fixes the problem) and there you have it.
Now when you insert Visio drawings into Word as embedded objects, your dashed lines will show up correctly and will print properly as well.