[Svnmerge] merging from branch to trunk and then to branch

[JL]

Hi all,

I've just stared using svnmerge and was interested in the best way of 
doing the following.

I have a development branch which I merge into the trunk using 
svnmerge.  'svnmerge merge --bidirectional'

When I commit these merges into the trunk I get a revision number. (eg, 
revision 52).   The problem is when I go back to my branch and use 
svnmerge to update the branch with the latest trunk changes, it sees 
revision 52 as a revision available for merging, and when it does the 
merge, it conflicts on all the binary files.  How do I indicate that 
revision 52 was actually a merge from the branch and therefore there is 
no need to merge it back to the branch?  I can 'block' it however this 
doesn't seem to be the right way of doing it.

Thanks,
Jeremy