I had to move a file within my project folders. After I moved it, xcode showed the file as missing (obviously). So I re-added the file via drag-n-drop into the project and deleted the old entry in xcode.
Now the "new" file is still in xcode, but for some reason for this filed code-sense and syntax highlighting is broken and if I try to build the project, xcode is complaining this file would be missing...
I already cleaned my project and also deleted the derived data, but it's still not working... Any other ideas? Starting to go nuts over here :(
EDIT: Btw, tried with xcode 4.1 and iOS SDK 4.3 as well as xcode 4.2 with iOS SDK 5
Ok strangely enough it worked after i added the file to another group than the one it was in before and as soon as i move the file back into the group it stops working again... Deleting the group and recreating it worked.