Problem with file_exists() and clearstatcache()...

I noticed the problem with the php functions, file_exists() and clearstatcache(). When I load a webpage, the php do the file_exists() and attempt to create one if the file does not exist. Then when I go to the next webpage, that file is removed. It is working pretty well. When I press refresh, it work okay. (removed the file upon unloading and create a new file upon loading). It work okay if I go from this page to a neutral webpage (with no file checking feature) then back to this page. It work great. But if I go from this page to the other webpage (with file checking), it showed the existance of the file even though there isn't one. So, I add the sleep() to see how long does it take for it to recognize that there is really no file itself. There I found that it take 40 or 45 seconds for PHP to finally see that even though it was already removed from the last webpage. Why is that? I tried with & without clearstatcache() and it have no effect. Is there some alternative to file_exists() that I can use?? I hope I'm explaining it clearly... FletchSOD