MySQL replication — issue with mysql.proc during replication from 5.0 to 5.5 host

Question

We are replicating from a mysql 5.0.45 host to a 5.5.26 host over WAN. Every once in a while one of our databases does not accept a query and halts the replication.

"'Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted' on query."

I found some useful information from this posting, but not specifically about replication. It seems like if you are upgrading, then you need to do the mysql_upgrade (with --force if needed) on that table. My guess is that the replication from 5.0 to 5.5 is like an upgrade...all of the time. So how would I do a mysql_upgrade here? If I do the upgrade followed by a slave start, will it be flushed out immediately as the data is still coming from a master without the upgrade?

Resolving issue with mysql.proc after upgrading MySQL from 5.0.* to 5.1.*

    mysql> show slave status\G
Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: 192.168.15.61
                  Master_User: replica
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000016
          Read_Master_Log_Pos: 1054186012
               Relay_Log_File: mysql-relay-bin.000431
                Relay_Log_Pos: 39375086
        Relay_Master_Log_File: mysql-bin.000016
             Slave_IO_Running: Connecting
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1547
                   Last_Error: Error 'Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted' on query. Default database: 'ResumeDB'. Query: 'INSERT INTO `search` (zip_code,lat,lon,dist)
SELECT zipcode,latitude,longitude,GetDistance( NAME_CONST('lat1',32.84), NAME_CONST('long1',-83.68),B.latitude,B.longitude) as dist
FROM zipcodes AS B
WHERE
B.latitude BETWEEN  NAME_CONST('lat1',32.84)-( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457)) AND  NAME_CONST('lat1',32.84)+( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457))
AND B.longitude BETWEEN  NAME_CONST('long1',-83.68)-( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457)) AND  NAME_CONST('long1',-83.68)+( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457))
AND GetDistance( NAME_CONST('lat1',32.84), NAME_CONST('long1',-83.68),B.latitude,B.longitude) <=  NAME_CONST('range',25) ORDER BY dist'
                 Skip_Counter: 1
          Exec_Master_Log_Pos: 1053930692
              Relay_Log_Space: 39635387
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 1547
               Last_SQL_Error: Error 'Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted' on query. Default database: 'ResumeDB'. Query: 'INSERT INTO `search` (zip_code,lat,lon,dist)
SELECT zipcode,latitude,longitude,GetDistance( NAME_CONST('lat1',32.84), NAME_CONST('long1',-83.68),B.latitude,B.longitude) as dist
FROM zipcodes AS B
WHERE
B.latitude BETWEEN  NAME_CONST('lat1',32.84)-( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457)) AND  NAME_CONST('lat1',32.84)+( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457))
AND B.longitude BETWEEN  NAME_CONST('long1',-83.68)-( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457)) AND  NAME_CONST('long1',-83.68)+( NAME_CONST('range',25)* NAME_CONST('rangeFactor',0.014457))
AND GetDistance( NAME_CONST('lat1',32.84), NAME_CONST('long1',-83.68),B.latitude,B.longitude) <=  NAME_CONST('range',25) ORDER BY dist'
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 40
1 row in set (0.00 sec)

This is fixed with a

mysql > slave stop; SET GLOBAL sql_slave_skip_counter = 1; slave start;

and replication picks up again. Obviously not a full replica of data when doing this more than a few times.