Excel 2007 : Need Help On Drop Down Boxes dissapear going from 2010 excel to 2007 excel

Hello everyone, this is my first post here I have a problem, Our company made some paperwork in 2007 excel with macros and formulas. The problem is when someone uses 2010 excel and forwards it to me for example( I use 2007 excel ) a lot of the drop down boxes have disappeared completely when I go to use it, but if I forward it back to that same person that uses 2010 excel the macros (drop down boxes) are still active.

I guess I should say that I'm using windows XP service pack2 so I can't upgrade to 2010 office. and I need xp to run other software for my job.

Any help would be appreciated

thanks In advance

SDF