NTDLL Debug Break Point?

Hi,

I have started to receive the following CPU window results seemingly without
trying. I have never seen this behavior from the IDE debug environment
before.

[CPU Window]
77F9EEAA ret
ntdll.DbgUserBreakPoint:
...

This seems to be a manually entered break point, but doesn't seem to be a
problem as far as interrupting the natural flow of the application by the
presences of any error or exception. Why does this happen? Is there a way to
disable it?