Include statement fails about 1% of the time

I've already been told that using include() statements is very inefficient and should be avoided. But... I've written a web app that uses them, and a little more than 1% of the time, the execution of the file that calls an include just halts right before or after the include. No errors, no nothing. Are include() statements really *that* bad? Or might there be something else in my system (Linux RedHat 7 right now) that could be causing this? I've only ever confirmed it happening when Win/MSIE connects via SSL, and have never been able to reproduce the problem from the user's perspective in-house; I've beefed up the SSL definition in my httpd.conf file to minimize problems with MSIE, but I've put a debug tracking mechanism in my code and have caught it not finishing code execution on about 1% of the page accesses. -Derrick