I changed the default max connections for MySQL from 100 to 1000 using Webmin v. 1.550. When I chose Save & Restart MySQL an error occurred and MySQL never started. I viewed the /etc/my.cnf and found the following line:
set-variable = max_connections = 1000
I removed "set-variable =" and just had max_connections in there and MySQL started up fine.
Which MySQL version are you running there? The version should be shown on the main page of the MySQL module ..
I tested this with MySQL 5.0.77, and the current Webmin behavior of using set-variable works just fine..
I have the same issue using MySQL version 5.5.30 and Webmin 1.560.