I'm just wondering if it is a bug as in bug, or if it is a logical consequence of collapsing the text region. If you were allowed to hide assignments in this fashion then you could set up a whole bunch of assignments and then hide them, completely destroying the transparency of the document, which is one of MathCad's virtues.
Hey fabcio, I was making a joke, don't take offence.
Cheers
Greg Locock