You can't just change lines in a patch file, you have to change the count as well...
authordrnull <jdhatfield@gmail.com>
Wed, 15 Jul 2009 13:04:15 +0000 (09:04 -0400)
committerdrnull <jdhatfield@gmail.com>
Wed, 15 Jul 2009 13:04:15 +0000 (09:04 -0400)
commitf2900f809215624f83c9302846bf3a5e8709e6cf
tree58b5e5938d298bf92447134858d899b07427f3fb
parent953c54a7a06b1bb9db186e82161059d5dda1df8f
You can't just change lines in a patch file, you have to change the count as well.  It would be better to make your changes to the actual files and regenerate the patch.
browser/enable-browser-downloads.patch