sybase DUMP TRANsaction to a dump device is not allowed

If you try this...

1> dump tran mydb to '/sybase_backup/tran.bkp'
2> go

and get this...

Msg 4208, Level 16, State 1:
Server 'DBSERVER', Line 1:
DUMP TRANsaction to a dump device is not allowed while the trunc. log on chkpt.
option is enabled. Disable the option with sp_dboption, then use DUMP DATABASE,
before trying again.

do this to fix the problem...

1> sp_dboption mybd,'full logging for all',true
2> go
Database option 'full logging for all' turned ON for database 'mydb'.
Running CHECKPOINT on database 'mydb' for option 'full logging for all' to
take effect.
(return status = 0)
1> sp_dboption mydb,'enforce dump tran sequence',true
2> go
Database option 'enforce dump tran sequence' turned ON for database 'mydb'.
Running CHECKPOINT on database 'mydb' for option 'enforce dump tran sequence'
to take effect.
(return status = 0)
1> checkpoint mydb
2> go
1> dump database mydb to '/sybase_backup/dmp.bkp'
2> go