Can't find a contact's phone number? If I tap on the dialer on a DroidX and start tapping in someone's number then when enough (usually 3) digits have by tapped in the person's name and number appear about the entry box and I can tap on them to dial.

However, if I go into Contacts and search for that same person by name they are not listed in my contacts.

I'm trying to work out what the disconnect between these "contact" lists are and how to keep them insync.

(I'm logged in with my gmail/google account and have a contact list on gmail which syncs with the phone.)
Can it be that you have unchecked certain contacts to be displayed ?

Go to contacts, press menu, more , display options and verify that you really display the names you want from the options on that screen.