I tried this from the IBM website, and it solved the problem:
Problem launching the DB2 Control Center
Abstract
An error regarding access to the JDBC server (CLI0622E), while trying to launch the DB2 Control Center might indicate a problem with your PATH.
Content
The DB2 Control Center uses services provided by the JDBC server in order to work with DB2. A CLI0622E error (Error accessing JDBC administration service extensions) indicates that when the Control Center was launched these services could not be found.
You should check your PATH for an \sqllib\bin entry. This entry must be associated with the drive and/or folder where DB2 is installed. If DB2 is installed in the Program Files folder of your C: drive, the entry would be C:\Program Files\sqllib\bin.
http://www-1.ibm.com/servlet/support/manager?rs=71&rt=0&org=SW&doc=1000788