Anybody have any ideas on where I would start looking to find out what's wrong here:

"Fatal error: Call to undefined function: is_writeable()..."

Since "is_writeable()" is a PHP function, how could it be undefined?

The script (OD FAQ) works fine, except this part that writes a new FAQ. I can add categories, etc. (It stores them in a text file.) Plus, I've got tons of other PHP scripts, both 3 and 4, running everywhere.

The only thing the author could figure out might be that there are too many users accessing the thing at once. But, in this case, it's just me.