Internal Server Errors and out of date SSI.php?

[Chucky]

In the last 24 hours my forum has suffered some minor problems, I call them minor because mostly everything still works for everyone.

One member gets an internal server error when he tries to read his PM's but he can still send PM's. No one else is experiencing that problem. Also, page 8 of a particular topic returns an internal server error for me.

I also found out that I'm using SSI.php 1.0.3 and it says the latest version is 1.0.6, I tried using the SSI.php file from the 1.0.7 (the version I'm using) updates and it still says I've got 1.0.3.

I wonder if I've CHMODDED the correct files... can someone tell me what files need to be 777 etc?