Some of the popup hints on my form are displaying behind other fields so that I can't read them. I suspect it may have something to do with the fact that the other fields which obscure the hints are from conditional questions.
My form is #5154.
I can duplicate the problem like this: for the question 'How many children will you be bringing', pick 5. then the fields for the five children will display. Select ages for the first and second children, and then the registration fields will display. Click on the registration fields for the popup hints to display.
How the form displays depends on the width of your screen. On my screen the field for registration of the first child is on the right side of the screen, and the popup hint displays OK. The field for the second child's registration wraps to the left side of the screen and the popup hint for that field is mostly erased by the fields for the third, fourth and fifth children.
P.S. I was using Firefox 2.0.0.11 on MacOS 10.5 I did not have the same problem with Safari 3.0.4. With both browsers the popup hint for fields on the right side of the screen went outside the edge of the screen and were not visible without scrolling the screen. Using Windows XP with Firefox 2.0.0.11 gave the same results, and something similar with IE 6 on Win XP, although in that case the fields that wrapped seem to be right justified, which is strange. Maybe it has something to do with the fact that they are inline fields?...
I'm working on fixing some other related issues with the popup field hints. I'll make sure to fix the problem you've encountered as well. I'll keep you posted.