Gaz - I feel I should also let you know that my experience of OpenOffice Calc, I think it was from OpenOffice 3 (and appeared to be unchanged from OpenOffice Calc v1), is that Calc is dangerously unreliable. It would often create random and often very basic calculation errors (e.g, copy drawing a load of increasing numbers - 1,2,3,4,5,7,8,9 ... wait where the **** is 6?) that I would have to get my colleague running the ancient but solid Excel 97 to fix stuff for me!
And this was just a reference table. Imagine doing anything involving money on something that thinks 2+2=5!