Sometimes PowerPoint files from much older versions of Office for Windows ('97 and below generally) come out a bit funny for me, but nothing major. The pictures and headings are usually in the wrong spot, that's all.
The only way I can work out to fix it (and it's rare so I haven't bothered looking for a better way) is to manually move everything back to where I think it should be.
I use office 04 a lot, esp excel, word and Powerpoint....havent had major issues, but I once had an excel template for some stats stuff where the date cell was on auto, but trying to print it on a PC and it was printing the date created and not that days...but as I said, no major issues for me....
Well I'm always using Office and as a student, a lot of it is collaborative work and has usually gone through about four or five different versions of Office before the final product is printed/shown or whatever. It's pretty much always fine.