Get a Red Question Mark when I try to send a text message on Droid RAZR

[snorin72]

I had to do a hard reset last week on my RAZR and since then I have a few contacts who when I try to send a text message I get a red question mark in front of their name and it won't send to them. I have deleted the contact in question and re-entered it but I still have the issue.
Any suggestions? This is a serious pain in the butt as I communicate frequently with clients via text.
Thanks,
Stacy