Referencing system views in SSDT?

Question

I've imported a database into SSDT containing a reference to a system view (specifically, sys.columns). The problem is, that I then get warnings about unresolved references when I build the project

From what I've seen on MSDN forums, it looks like it may be a known issue: http://social.msdn.microsoft.com/Forums/en-US/ssdsgetstarted/thread/5a7026bd-0602-42e6-a639-d73bed903c26

Now, I know I can switch the warning off or ignore it, but does anyone know of an actual solution?

Thanks