User and Member ID#'s - getting rid of cached memory

I deleted my whole multisite and am starting over again.

I am using Simple Membership to register new Members.

I imported 137 Users/Members and manually changed all of their User/Member ID#'s in phpMyAdmin so the ID#'s are consistent on all four domains. I now have Users & Members from ID#1 to ID#137.

When I register a new member and then check the ID's, instead of it being #138, it is User ID#2481 and the Member ID# 2440. Obviously it is remembering ID#'s from before, probably from the import process.

I did a "sweep" of all sites, but the system just can't seem to forget its past. How do I get rid of this cache so that my numbers will continue sequentially from 137?

Support access is granted.
Thank you.