Select All buttons on User notifications tab work strangely

On http://example.com/user/1/notifications/taxonomy/?destination=/ there are two boxes at the beginning of each list for selecting or deselecting all listed forums or file posts. The mouseover text on the two boxes at the top of the list of forums is opposite to the described behaviour - when "Deselect All" selects all, "Select All" deselects all. The mouseover text on the two boxes at the top of the file category list is identical for each box, but selecting one or the other box works as expected (except deselecting all leaves a check mark in the "Select All" box. Selecting "Deselect All" on the File Category list will also deselect all the selected forums in the list above (or below).

On another installation of mine there is only one checkbox showing up, and it seems to be working properly. On this installation, I had originally had 5.x-1.0-rc1 installed, and this problem had occurred. I upgraded, but am unable to delete the original module directory (though I had renamed it to sites/all/modules/notifications 5.x-1.0-rc1 already and called the new 5.x-1.2 version sites/all/modules/notifications). The 5.x-1.2 version is what is currently enabled.

I don't know whether anyone else has had this problem, or if the strange behaviour of the checkboxes is specific to my installation.