Filing P35 Employer's Annual Return from HMRC's CD Basic PAYE Tools

I tried filing my own P35 from the HMRC's CD "Basic PAYE Tools", and it failed - citing incorrect user ID/password/PAYE reference (no detail as to which) – yet all were correct that I could see.   I tried a couple of times, as was warned about the ID/password being case sensitive (although they’re not through my usual log-in route) then gave up, and filed my P35 via HMRC's website filing only routine - manually entering all employer and employee information again. Another pain in the butt, though, is that without successful completion including online filing of the P35 from the CD, I was unable to process any entries for 2011-12, so I have had to set up a new database entry as if for a new employer and enter these and employee details afresh yet again.