I've been trying to install (1.3.14) on a shared host (hostmonster), but have been running into problems. I had everything set to 0755 but got a 500 error until I changed the permission on the index.php to 644 and then things started to work. That doesn't make sense to me, but it was the only way to get by the 500 page.
I've been able to access the database and the wiki but when I try to login I get

Fatal error: Non-static method _PearDbPassUser::_PearDbPassUser() cannot be called statically, assuming $this from incompatible context in /home1/..../wiki/lib/WikiUserNew.php on line 1118

Clearly this is indicative of a deeper problem in my installation, but what?

You can see the behavior at http://physandmath.org/wiki