Just for info, I too have this happen to me. We are using Filemaker Server 5.5 and the clients are all using a mix of v5.0, v5.5 and v6.0. I am using v6.0 dev and v7.0 dev.
It is not related to the version of Filemaker you are using. It seems to only affect OS's. Here are my findings:
Windows Server 2003 - Layouts are in a single, scrolling column,
Windows Server 2000 - Layouts are in a single, scrolling column,
Windows XP Pro - Layouts are in a single, scrolling column,
Windows XP Home - Layouts are in a single, scrolling column,
Windows 2000 Pro - Layouts are in a single, scrolling column,
Windows NT 4.0 - Layouts are spanned across the screen.
I can only presume about Win 9x but my guess is that it performs in the same way as NT.
I personally prefer mine across the screen as with NT.
