Creating active timers within callbacks

Hi,

I'm writing a daemon utility (https://sourceforge.net/projects/scumd/) 
that I'd like to spawn off timer-based watchers from within an io-based 
watcher callback.  The timer watchers created are returned when I do a 
all_watchers(), but their callbacks are NEVER subsequently executed 
(even with PRIO_HIGH and a hardcoded short interval).

Is there anything more I may need to do for the timers to be active?  
Also, if there is more documentation available in addition to the 
perldoc, that would be very helpful.

Thanks,
John