When starting an acquisition, the GUI elements allowing manipulation of the device settings aren't disabled. This means that e.g. the sample rate of the demo driver can be changed after aquisition has been started. This results in PV messing up the display and no longer immediately responding to a user's request to stop acquisition.
Thanks, fixed in 73e170f93ce9deb7bba04966564dcd8af8dfe7e1.