wow. too many different issues in one post! 
Debbie, so you have to go to forum – usergroups – manage usergroups and manually add the members to the desired usergroup… the auto only works on new users… we have a ticket to add a tool to add in this, but no eta…
Tony, confused… how many rows in sfmembers? that should be the number of users the stats displays… stats are cached at 1 hour (user selected in 5.0.5)…
Do you know that your wp cron stuff is running and working? the stats use the wp cron to do their thing… you could try deactivating (DO NOT uninstall) and then reactivating SP… That will make sure our cron jobs get restarted, but wont help if its wp issue…
if that does not help, go to your blog and create a new wp post… just a test post… schedule it to be created in 10 minutes… and see if it appears… should verify if wp cron stuff is working…
also, edit your spFunctions.php in your sp theme… add this line at the top:
sp_cron_generate_stats();
and see if the stats update… that will force the stats to generate on every page load… wasteful and overhead but at least verify the functionality is working…