SVN marks entire files as conflicted

Question

I'm new to SVN. After working on a branch for a day or so, I attempted to merge changes from the trunk to the branch:

svn merge svn://server/trunk

The problem is that whenever SVN encounters a conflicting file, it's not able to recognize line by line changes and marks the entire line as conflicted. I experimented with several other SVN clients and also tried to toggle the end-line and white-space options without any progress. What am I doing wrong? I think this is the simplest possible merge case, so I would expect this to work with the most default Subversion settings, any client and in any SVN version. Is it some known beginner's catch?

Client: 1.5.5 (SlikSvn:tag/1.5.5@34877) WIN32

Server: 1.4.6 (r28521), Windows

Edit

Based on the suggestions in comments and answers below, I did more investigation:

1. The problematic files are UTF8.

2. They don't have any SVN properties.

3. The "svn diff" command correctly identifies the differences.

Answer 1

We had this issue recently and found that it was a problem with using a 1.4.x server and a 1.5.x client. Subversion 1.5 introduced more intelligent merging but you need the server and client to be running 1.5 to take advantage of this.

We found that specifying the range of revision numbers that we wanted to merge gave the expected results.