serious problem with linked files i VS!

[ORC]

Applies to C#, Visual Studio 2003 version 7.1.3088.

I have a project where I have several linked files included. One problem is
that when I make changes in one of the linked file I will have to restart
the editor in order to update the intellisence. Another more serious problem
I have encountered, and that I'm really strugling with, is that there
somehow seems to be a limit or something to how many linked files/namespaces
that can be included. In one of the linked files I write:
using nameSpace6;
where nameSpace 1 to 6 is located in another linked files. But the compiler
shows this error when trying to run the MyApllication:
"The type or namespace 'nameSpace6' could not be found(are you missing a
using directive or an assembly reference?)"

There is no problem with the linked files 1 to 5 and I have tryid to check
and double check, change namespace, reload the files, restart the computer
and the editor several times, created file with just the namespace without
anything else in it - Nothing helps!

Is this a known problem? is there a workaround? Please help!

Thanks
Ole