As I have already mentioned elsewhere, just because you can perform an automatic merge, it does not mean you should do it. Automatic merges can create bugs unless you methodically check merge results. I have found checking after the merge is not as straight forward as checking when the merge is being performed. Working as a merge/release manager, I saw bugs generated with automatic merges and so generally manually merged, checking each difference before moving on. Turning off automatic merging should be a simple feature to add to SVN rather than having to perform tricks to achieve this.