Subversion unable to merge changes when using Dreamweaver

I've got a project running and we're using SVN as the version control. There are 3 devs on it.

Dev1 = OSX + Textmate

Dev2 = Windows 7 + Dreamweaver (plus tortoise svn)

Dev3 = OSX + Coda

Case 1 (expected):

Dev1 and dev3 work on a file called signup.php. They work on different parts of the file. Dev1 commits it and dev3 updates their copy. signup.php is merged as expected. All good.

Case 2 (not expected):

Dev1 and dev2 work on a file called signup.php. They work on different parts of the file. Dev1 commits it and dev2 updates their copy. signup.php is always in conflict even though different parts of the file are worked on. This is not the expected behaviour experienced by dev1 and dev3. This works boths ways and each time dev1 updates dev2's changes he gets conflicts too. But never with dev3.

Could this be down the way Dreamweaver is saving files ? Perhaps character encoding. We are all working in UTF8.

These constant and unnecessary conflicts are becoming a massive dist开发者_Go百科raction. Help !

This might be due to line endings being encoded differently between Windows and OS X: whatever the developers change, the entire file's line endings get updated to what's native for the platform.

What svn properties does this file have?

If it has a svn:mime-type property set that doesn't start with 'text/' than Subversion sees the file as binary and you will always have to resolve conflicts by hand.