postgres 8.2.9 can't drop database in single user mode

i'm getting the following error.....  any ideas why this would be in
single user mode??

backend> drop database "scoogan_userprofile_1.2"
  2009-04-21 18:18:23.032 EDT  [11767] [] WARNING:  database "ange" must
be vacuumed within 976081 transactions
  2009-04-21 18:18:23.032 EDT  [11767] [] HINT:  To avoid a database
shutdown, execute a full-database VACUUM in "ange".
  2009-04-21 18:18:23.053 EDT  [11767] [] ERROR:  database
"scoogan_userprofile_1.2" is being accessed by other users
  2009-04-21 18:18:23.053 EDT  [11767] [] STATEMENT:  drop database
"scoogan_userprofile_1.2"

backend>