I recently stepped over the issue, when registering new rss folder in zcs web client (v7). All feeds (in this particular folder) appeared to be messed up with encoding. Looking via Firefox rss link (UTF-8) everything is ok. Importing this feed in Google Reader - againt, UTF-8, everything is ok. But in Zimbra Web client - all accented characters look like from different encoding, although ZCS WC is on UTF-8 too.
Could it be a problem of server OS default encoding, or Default MySQL encoding for ZCS? Have not seen such problem with other sites in Latvian. I understand, that these issues could be connected with source site configuration too, but test for Google reader proved, that these feeds can be imported correctly.