bone targets problem

[monalotfy13]

hello..

There's a problem with the bone targets.. I created a target bone for the shin.. it works properly at frame zero but when I try to move it at any other frame the bone transforms on its own and the shin stays in place as shown in the picture below and i'm not able to manipulate it anymore
http://i.imgur.com/KlLdIsK.jpg
have anyone had the same problem before to tell me how to solve it?

[Umikron]

Almost the same problem, but when I start moving bones target bone disconnects and I can't operate other bones. To make things even worse some vector layers became invisible (but on preview everything is ok).