MD5 vs. CRYPT

There are two ways to encrypt passwords in lockdown MD5 or CRYPT.

By default you should use MD5 -- It's a better way of working. The only reason I would recommend MD5 is if you host uses a so-called "Zeus" server. If you don't know for sure you can test it with the handy-dandy server testing tool (it will tell you if you need to use MD5 or not)

If you are having trouble getting lockdown to recognize your passwords you can also try converting to 'CRYPT' format as that will sometimes help.