Adjusting the size of the dock - can't do it by dragging or in System Preferences

[0dev]

I can't drag the bar between the applications and folders in the dock to change the size - nothing happens. I can't change the size in System Preferences - the option is greyed out.

I vaguely remember, quite some time ago now, I may have used some sort of OS X tinkering app to lock the dock. Usually I have to run some sort of Terminal command to undo my meddling, but I've Googled and I can't find anything useful.

Any help? Thanks

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Never mind, did a bit of messing about and found the following command worked:

defaults delete com.apple.Dock size-immutable

Then of course I did killall Dock to make it take effect.

Sorry