Working IDL Rule?

Does anyone have a working IDL rule?

I actually have a working IDL rule, but only for "simple" structures. 
 I'm building a static library (no nested source directories) in a 
directory which contains both C/C++ files and some IDL files.  This 
works just fine.  However, I also have a "shared" subdirectory for 
creating the shared objects/library from the same C/C++ and IDL files 
(only the .o's and .so's go in it).  This works just fine, too, but it 
regenerates the C++ files from the IDL files in the TOP directory (it 
doesn't need to do this ...), which forces uneeded re-compiles when 
running Jam again (as the static library is now out of date).

I'm convinced it is either a gristing or dependency problem, but I'm 
pretty stumped as to where at the moment (I've spent a few days trying 
to get it all working).  If anyone has a working IDL rule for this type 
of setup they could share, I'd appreciate it.

Thanks in advance,

/dev/mrg

PS. I could post a lot more details if needed, but thought I'd try a 
more sparse approach first.