an adp page is compiled once per thread and the tags themselves emit tcl code. You see it invoked for each thread (which is why you see it called 4 or 5 times) but then once the template is compiled the tag is no longer invoked.
If you touch the source .adp it will recompile it again
so if you are working on the tag thats probably the easiest way to ensure it gets invoked when you change it.
The best place to start with what is admittedly a pretty dark art is to look at the existing tags, or turn on developer
support which will include links in the footer to the compiled
version of each template (the little "c" link).
