This is a nightmare in IE. Whenever I flip the div (display:none display:block) I get a blank space (another words, the div is not collapsing properly). Anyone ever been able to do this properly in IE? Other browsers behape as expected.

I have had the same problem - what I have done is use a table then place each div inside its own cell. If the cell is "empty" (i.e., display:none) the table cell collapses and the extra space should be gone.

what I have done is use a table then place each div inside its own cell

Totally unnecessary.. and there's just no point in using divs if you're going to stuff them inside a table

Where is the problem page ? Have you got one where the empty space is showing ?