debugging

Can anyone give some guidance on this scenario: I've embedded Boo as a
scripting platform in an application.  It is using the
CompileToMemory pipeline (by design choice).  I want to set a
breakpoint (for now, I'm just inserting a call to System.Diagnostics.Debugger.Break())
and run the script.  When I run the script, visual studio does
stop at that point, however it doesn't have any sources for that point.
 I've confirmed that it is generating a PDB for my script file. 

 Any suggestions? Thanks!