Please don't give up. I would take a stab and say that 98% of reunion organizers of African-American family reunions experience this problem, especially with the first family reunion. Even with the 5th or 50th reunion, this is still a classic problem. Lords know I can't count the number of times I've fussed about the slow pace the money arrives. Then, the week of the deadline and a week AFTER the deadline, my mailbox is filled with incoming money and registration forms. And the flow continues until a day or two BEFORE the reunion, despite the fact that the letter clearly stated that the deadline was a certain date (normally a month before the reunion). I've even had family members FED-EX me their registration fees a day before the reunion, and called me while they were on the road on the way to the reunion to see if I got it!! LOL! So yes, we all feel your "pain", but hang in there. Everything will fall into place.
One thing that seemed to help were periodic e-mails to family members. My family has a Yahoo group with over 90 family members subscribed. So we use that to send out reminders about deadlines because you'll be surprised at how many people misplace the reunion newsletters and forget about the deadline!!
Much Success With Your Reunion,