Made you it test in your medical system with listview grouped? The error is in the sorting of the itens. Rogério Mauri
It makes the test with the grouping option. Rogério Mauri
We actually have this running on a lot of Server 2003 environments in our medical software and I just verified this again...so I don't think that this has anything to do with it. There is the possibility that a core Windows component is not right, but I really doubt it. The ListView only uses the API for rendering certain components, but the control itself is actually written in .NET and so the behavior, such as sorting, will not be influenced by the OS. And especially this, as this is exclusive to SF, I know that the OS has nothing to do with this part. You might look elsewhere and see if you can replicate this in some other environemnt, but I am confident that Server 2003 is not your issue here.
WindowsVISTA - OK
Windows Server2003 - NOT
Rogério Mauri