Just as a small tip, I noticed that when you call pspell_new multiple times, php does not free memory usage when the resource is destroyed, but only when your entire script has completely finished. So if you create a pspell_link resource and you intend to use it again somewhere else, instead of calling pspell_new again, keep track of your original pspell_link resource instantiation, and use it again, your script will run much more efficiently.
I was switching between 16 dictionaries by just calling a new pspell_new everytime, my memory usage on the server grew until i hit a failure/php core dump. :-/ So i stored each pspell resource in an array keyed by language, and checked if the resource existed first, before creating one if needed.
I hope that helps someone.