IIS and MSSQL dates using hidden default locale setting on Windows Server 2003?

So, this is an old problem but I would love to get to the bottom of it's cause, rather than the workaround...

I have an ASP.NET site which uses a MSSQL 2000 database.  On one web server, it displays everything correctly with UK date formats dd/mm/yyyy as expected throughout the whole site.  But on another server (Windows Server 2003), any query that returns dates, comes back in US format mm/dd/yyyy.  The MSSQL server is the same in both cases.

Now I know I can put LCID=2057 in each of the pages of the site to combat this issue but I would really love to know what needs to be set on the server to enable everything to run in UK format by default.

All the regional setting in Control Panel are set to UK.... what's going on?  Is there a hidden default locale setting in the IIS metabase or something?

Help appreciated...