I bow down to you Jason, when I gave the menu a height and width I did it to the top level instead of the drop down level. So now I have given the height and width a value which didn't appear to work as the menu was behind everything, but I positioned the outer containing div as relative and gave it a z-index of 5 and the inner menu div as absolute and gave that a z-index of 10 and hey presto it works hallelujah.
Although can you have another look for me as the 1px border I have applied to the bottom of the drop down dosen't appear in ie7 so it replaces it with a gap which will close the menu if you hit it see: aiprocess/
Many thanks Jason I have gone totally grey over this but you have saved me from pulling the rest of my hair out regards Alistair