Not for me it isn't. Mine always shows the username column selected for a descending sort (the column is highlighted and the column header has the arrow to the right). It isn't actually sorted by username or any other column, and clicking on any column header makes no difference (username remains selected, no sorting occurs).

Not sure if this has been fixed yet, but I'm using KDE 4.3.1 and I've never been able to sort the columns in that 'thing'. I'd probably use it a lot more if I could sort, but instead end up falling back on opening up htop in a konsole.

Wierd, I have not had that happen to me.

Are you by any chance using any extensions that modify the page source or page rendering in any way?

Can anyone comment on what specifically causes the problem? (like a broken tag for example)