Hi Bill,
I received yesterday my UCAC4 DVD from USNO. I copied the files into a new ucac4 folder I created below the c:\guide9 folder. I then updated the startup.mar file adding the string "UCAC4_PATH=c:\guide9\ucac4". I started GUIDE (test version, 29 may 2012 release) and no UCAC4 stars were shown. I closed GUIDE and checked the startup.mar file, finding, to my surprise, that the previous line I added was no longer there!
Any idea? (I'm running the 64 bit version of Windows 7)

Thanks,
Claudio