Here is a quick and effective solution to some Compur shutter problems.

It does not involve lighter fluid (not pure enough for these delicate mechanisms, as it leaves a residue).

It does not involve bathing the shutter unit (a practise which will remove all factory lubricant)

It does not require a major strip down to re-lubricate (perhaps only required in the very worst cases)

It has proved successful in virtually all shutters with ‘sticking’ slower speeds.

This method (given for the Compur found in a Rolleicord Art deco) is simple, works and can be found here: http://www.pbase.com/raynerj/repair