I'd put kjsimons' suggestion above this one, but just an additional thought:
Perhaps the password change "pushed" the error through the system.
That is, once you changed the password, whatever was messing up is no longer present - maybe it was on your hardware/software side; maybe it was on Percy's software side; maybe a bit of both; maybe no actual "error" but more of just a strange "mis-alignment" - doesn't matter - it's gone now.
If this is correct - you should be able to change back to your preferred password and everything should be okay.
But - if there is an "offending character" as kjsimons suggests - this will not work.