We now use svn:keywords "Id" on all .c/.cpp/.h/.inc/.sp/ files.
Please make sure your client is configured properly.  

WINDOWS:
	- Open your Application Data directory.
		Windows XP/2000:	C:\Documents and Settings\<user>\Application Data
		Windows Vista:		C:\Users\<user>\AppData\Roaming

	- Now go to the Subversion directory.
	- Open the "config" file with a text editor.

LINUX: 
	- Open ~/.subversion/config with your favorite text editor.

Under [miscellany], uncomment this line:
# enable-auto-props = yes

Under [auto-props], add these lines:
*.c = svn:keywords=Id
*.cpp = svn:keywords=Id
*.h = svn:keywords=Id
*.inc = svn:keywords=Id
*.sp = svn:keywords=Id


If you find a file with one of the above extensions that does not have the svn:keywords property...

TORTOISE SVN:
	- Right click on the file(s) that do not have the property.
	- In the context menu that appears, select TortoiseSVN -> Properties.
	- A properties window should appear. Click the Add button.
	- Select "svn:keywords" from the "Property name" combo box and type "Id" in the "Property value" text area.
	- Click OK on both windows and commit the change(s).
	
CLI SVN CLIENT:
	- Execute the following command: svn propset svn:keywords Id <files>