I believe you'd need to upgrade to 6.7.3 (found in the members area) then import into threads. I've done it many times without issues (ok, maybe only a hundred times).
webintellects has nothing to do with how your forum runs, but they do their webhosting job topnotch - ask for a server with plesk 8.1 running and you'll get the latest software available. Their tech support and the server reliability has been the best I've ever used and I've been running websites more than 10 years now.
