MySQL parameters set through Webmin use syntax of the form
set-variable=max_allowed_packet=1G
This is deprecated and should now simply be for example:
max_allowed_packet=1G
# mysqld -v
121018 13:29:54 [Note] Plugin 'FEDERATED' is disabled.
121018 13:29:54 InnoDB: The InnoDB memory heap is disabled
121018 13:29:54 InnoDB: Mutexes and rw_locks use GCC atomic builtins
121018 13:29:54 InnoDB: Compressed tables use zlib 1.2.3.4
121018 13:29:54 InnoDB: Initializing buffer pool, size = 128.0M
121018 13:29:54 InnoDB: Completed initialization of buffer pool
121018 13:29:54 InnoDB: highest supported file format is Barracuda.
121018 13:29:54 InnoDB: Waiting for the background threads to start
121018 13:29:55 InnoDB: 1.1.8 started; log sequence number 1595685
121018 13:29:55 [ERROR] mysqld: unknown variable 'set-variable=max_allowed_packet=1G'
121018 13:29:55 [ERROR] Aborting
121018 13:29:55 InnoDB: Starting shutdown...
121018 13:29:56 InnoDB: Shutdown completed; log sequence number 1595685
121018 13:29:56 [Note] mysqld: Shutdown complete