When used in matrix procedure panels, info(“matrixrow”) returns the number of the matrix row clicked when the rows are clicked in any ascending numeric order, but retains the previous matrix row number when rows are first clicked in any descending order.
I discovered this using 10.2 b13, but it also happens in 10.1.2. I must say I find this very hard to believe.
Enclosed is a .gif of a very basic test matrix, created with the constructor, showing this.