The old RIS format for citations, which Procite reads, uses tags followed by one space. The current RIS format, which RefMan reads, uses tags followed by two spaces.
This isn't documented anywhere that I can find, and there was no version number change. The specification pages for the RIS format state that there should be two spaces, but the examples still only use one space.
Hopefully, the Procite RIS config files made available for RefViz should be able to deal with the double spaces.