I have the same issue, after selecting a friend ( I send out a message to a big group of friends about an event) it just shows their number instead of their name like the default app. Makes it harder to keep track of who I already selected.
Also another thing is I'm on Droid 2 running 2.2.2 and Handcent doesn't list "Mobile" or "Home" anymore when I start typing in a name; example
Chris
and it shows 2 Chris numbers, but it would used to say mobile or home. It still shows it if i Highlight it but that's extra work.
To "fix" this I just set hadncent to show only mobile numbers....but I would prefer to see every number available I have on a contact