I imagine this has already been discussed and fixed. I was going completely mad trying to make the dropdown menu work, only to discover that the reason that I havent been able to do this is that the tutorial has an error.
At the point where it shows the indiviual blue buttons mouseover it shows a 'then show' action instead of 'hide it and show'.
I can make them with my eyes closed now...ok thats not true.

I think you are referring the the image (obj 2117 - "DropOne.png") under the heading "Mouse overs on menu pages" on the tutorial workpage.

If you have the Z-order the same as the tutorial, either way should work -- 'then show' will work the same as 'hide it and show'. The reason is that the light blue button sits on top of the dark blue button. So a straight "then show" targetted at light blue will cover up dark blue. With dark blue covered by light blue, it doesn't matter whether you also "hide" dark blue.

If your Z-order is different from the tutorial, it is possible for an invisible object lying on top of a visible one to interfere with the link on the visible one. Firefox is susceptible to this -- but was OK for a simple test I did just now.