I have a user that has is using a Blackberry 8330 with firmware 4.5.0.169 installed and on the BIS server, it has wireless upgrade set to false. I can't figure out why that is.

On the other hand, I happen to have another user that is using the same 8330 with the firmware 4.5.0.77 and his wireless upgrade is true. I can't seem to figure out what I have to do to enable it.

What wireless carrier?
If the carrier hasn't approved 4.5.0.169 as a valid source version, then the user won't be able to do a wireless upgrade.