Question : Pix 525 Configuration

Why does doing a clear xlate on a pix 525 allow vpn tunnels to reconnect?

Answer : Pix 525 Configuration

why wouldn't it?  clear xlate just clears the NAT tables (which are dynamic).  So anytime a new NAT is needed one will be recreated dynamically.  To see what is currently in the NAT table, run show xlate.  If you run a clear xlate it will be cleared but only for a few seconds until the new NATs are re-created.

If you have some specific problem please explain it.  It is kind of hard to help you with such a general question though.