I am having problems with my SQL server Agent.

1) When I try to create a New Job/Alert/Operator, I get an error message:

Error 207: Invalid Column Name "category_id"
Invalid Column Name "netsend_address"
Invalid Column Name "last_netsend_date"
Invalid Column Name "last_netsend_time"

.....All these are referring to columns in System Tables of the system Database MSDB.

2)In another SQL Server...say "A", in it's SQL Server Agent, using the Multi-Server Administration, I set up the SQL Server Agent of "A" as the Master (MSX) server, and set up a Target(TSX) server pointing to the Server "B" that has problems in SQL Agent....referred in 1) above. When I try to "Detach the MSX Server" from server B, i get a message Error 207: Invalid Column Name "netsend_address", and cannot detach..........This is again referrring to a System Table.

It appears that the problem is with the MSDB database being corrupt. Is there a way I can Repair a Corrupt MSDB without Re-installing SQL Server 2000 and without a Backup.

Any help greatly appreciate.