Hi John,
I’m going to guess you’re on a shared server. If so, your blog or someone else’s may be exceeding Google’s rather low geocoding limits. You can see more about this problem in the FAQ.
You can sign up for Google Premiere or move to a non-shared host, but the easiest thing to do is probably to just geocode those points you want to map before mapping them.
I’m guessing you’re mapping them by address using PHP code? If so, you can either
1. Save the points to a map in the map editor (which will geocode them) and then map them using a mashup
2) Or determine the lat/lng for each point and use the lat/lng in the map instead of the address. You can use one of the many free geocoding services for this.