Anyone knows how to get rid of the annoying de-dum error noise when TheBat cannot connect to a mail server?
Win7

It seems to be a system sound, at least it comes in on the system channel (otherwise I'd have muted TheBat in the volume mixer already!).  
Edit:
I do not want to disable all system sounds, not even the error noise, only ensure that TheBat does not invoke one.

Any ideas, please?
Thanks!