Keeping your password concealed should be all that is necessary.
QUOTE(Yoshi)
If you use it in more than one place then here, you should be worried.
Yeah, I agree, if you keep that in mind, everything should be fine.
I'm not sure how Invision does its password handling, but you'd think it'd be good enough so if you see the encrypted password in the database you couldn't take it, copy it into your cookies and login as that person.
I don't know if I need to bother with typing this up, but, the safest way is to have the passwords in the database encrypted twice (or more) times with some one-way encryption/hashing function like md5. When you type in your password in the webpage to login, it's encrypted once and that is set as your cookie.
In the database, your password would be encrypted twice, and so to check it, the page would take the password in the cookie, encrypt a second time, and then compare that to the database.
This is secure because even if someone does have access to the password database, they would only be able to see the passwords encrypted twice, and so they can't login or spoof cookies since they wouldn't be able to work out what the string for the password encrypted once would be.
Although, I would presume Invision would be clever enough to know this. But who knows, you might as well check how the passwords are handled if you've got nothing to do.