Thank you.
Ok, the Total Registrations are the total regsitrations you have EVER had on your board. When you delete accounts for whatever reason, the Active Registrations are what is left. That is the ACTUAL number of memebers on your site. Does that make any sense.
As far as the userids not being correct, follow the instructions above and delete those lines and when the next cache update is run, it should straighten everything out for the userids.
Also, make sure you have the referrer sysem enabled in the Admin CP. If it is, then you missed a piece of code when installing the hack. Look at the spot where the name should be in the code and tell me what is there right now.