i finally figured out what annoys me a lot about several "buttons" in zabbix
try clicking on any of trigger severity buttons and slightly move the mouse cursor. nothing happens. a click is only registered if mouse cursor is completely stationary.
normally buttons operate if both mousedown and mouseup are in the button area, and zabbix buttons should do the same.
this affects pretty much all buttons, but with global search one it is weird :
try clicking and dragging vertically to the left of "search" text - nothing happens. now try the same on "search" text - it works
this is with opera 12.16 on linux