How to find amount of time spent and number of times that own function is called?

I recently started to use Profiler with the hopes of using it to find performance bottlenecks, etc. I have found the results quite difficult to use (or perhaps, it is a problem that the documentation is not detailed enough). For example, I would like to find the number of times (and amount of time used) that my own sub-functions are called by a higher-level function. However, the results seem to be sporadic in including these sub-functions in the results. Is there a way to specify the detail level of the Profiler to only include user-defined functions and/or to show all usage of user-defined functions?

[Jan]

What does "the results seem to be sporadic" explicitly means?

[Robert]

I meant that only a subset of the called sub-functions are included in the profile report. I can't figure out any pattern to which one's are included, and I would expect all of them to be included.