ZBrushCentral

trouble with masks

I am using Zbrush4 on a mac - My problem is that masks that I make on a model in sub tools seams to get baked in and no matter what i do after that It keeps becoming active causing all sorts of problems??

Sounds like this?

http://www.zbrushcentral.com/showthread.php?t=95808

Hth,

Sam