Some one help I'm getting crazy: Flash Builder 4.6 - debugging mobile on desktop : Process terminate

Hi all,  I am working with FB 4.6 on a windows 7pro 64 bit I'm working at a mobile android project.  I can debug it perfectly on device but if I launch it with the desktop emulator the debugger never connects.  Once I close the AIR window I got "Process terminated without establishing connection to debugger", and all the trace commands.   I am just noticing that both Android and Desktop have the ***IDENTICAL**** version of adobe air 3.1.0.488   Anybody can help on this? I have a bunch of network connections to debug, and it would be extremely easier to test the app on the desktop FB environment  I have tried the most common things: clear project, create a new workspace and re-import the project, run FB as an admin and also re-installing the AIR runtime.  Also I have the lastest JRE  Thanks  Alfonso