Hello NI,
debugging a program that uses tooltips may get complicated because the tooltips persist on the screen - they float above all other applications and thus it is impossible to get rid of them, this includes the IDE: it may happen that at a breakpoint the program stops but that the variable window or the source code is (partially) covered by the tooltip... since the tooltip cannot be moved it may render debugging impossible. This means that one has to take great care that no tooltip is shown during debugging...
I feel that this is undesirable behavior: at a breakpoint the tooltips should 'disappear', too.