I just installed the 4.50 update. There seems to be a problem the details page with Chrome. It works ok with IE8 however. Attached is a screen print of the results with Chrome.

It appears now that the problem has gone away, and yes, I'm embarrased for having raised the quesstion.  Perhaps there was some cache clearing needed after the 4.50 update.

But thanks for the reply anyway - and FYI none of the matrix boxes are checked in the product details page. 

Dave