PHP requirements

Hi, I used this module with success on a 5.7 installation (importing from WP 2.5.1).
One things I ran into:
- If there is a second user, all categories are imported twice. I solved this by deleting the second user from Wordpress, assigning his stories to the admin.
- More serious: on my hosting platform, the import resulted in a white screen. It turned out that only 199 of the 225 stories had been imported. This was probably caused by a massive number of Log messages.
- I discovered that PHP 5 was necessary for WPI to work properly. I had this available on a local WOS-installation.
Exporting the SQL5 database was possible with compatibility options set to SQL 4.

So my suggestion is to place a requirements warning in the user documentation.

Thanx for the great work.