Two notes:
^
in SVN-path means always repository-root, thus^/c/branches/ovm_sequencer
implies "/c/branches/ovm_sequencer" inside repository, while you have (most probably) repository inacme.com/a/b/c
path, and URL must be^/branches/ovm_sequencer
"Retrieval of mergeinfo unsupported" means one bad fact about your Network|SVN admin - he doesn't read Release Notes for updated software: in order to have mergeinfo supported on server side except updating software for pre-1.5 Subversion to 1.5 or later, repository also must to be upgraded in order to have new format. Topic (very old - from 2008 year) on Collabnet "mergeinfo not supported"