Capture Scratch cannot be changed

Hi Guys,

wondering if anyone else had come across this problem with Final Cut 7 on a mid 2012 macbook pro. Up untill now i have been able to set my capture scratch with no problems but recently whenever i try to set the capture scratch either from starting up FCP or from the system settings menu, the dialogue box that appears normally when you click on set appears for a second or two then dissapears? Each time i press set the same thing happens - appears for a second then dissapears meaning my capture scratch is saving to whatever place it was last saved i.e desktop etc.

Any ideas?

Thanks🙂