I don't know if this is specific to 6.42 or to Vista. I'm using the RAPI library, B4ppc 6.42 and Vista with Windows Mobile. The RAPI library produces the connected and disconnected events when run in the IDE but file transfers always fail. Legacy or optimise compile the same code and it works fine! EDIT: - It looks like the IDE thinks it is permanently connected and fires the connected event when the app starts. I think that I am wrong about the disconnected event, I don't think it fires at all. EDIT:- This is most confusing. The problems seems to vary. I'm getting different symtoms today trying to run in the IDE. To begin with I was getting something like "value not expected" exception when I did Rapi.connect and then all of a sudden without changing the code, but having exited and restarted B4ppc it has started working? This is very strange!! EDIT:- What happpens seems to depend upon the order of doing things. If I start B4ppc then connect the device then run my app in the IDE it seems ok. If I exit my app (but not B4ppc) disconnect the device and rerun my app I get a "Value does not fall within the expected range" error on Rapi.Connect. If I now exit and restart B4ppc and run my app then Rapi.Connect does not throw this error.