There are commands to do this with in the command line field.
":AutoRefresh 0" will turn off all auto refresh.. need to restart MC. and then you need to press refresh you select to refresh.. it will not monitor folder for changes..
":AutoRefresh 1" to turn it back on..
or if you temporary want to stop it for one folder..
":UnwatchFolder <folder>"
(See Application Log Ctrl+L for information it they turn on / off )
":FolderMonitor List"
To list all folders that are monitored