of course you can't. This issue was mentioned hundreds of times already, and was caused by legend. Due popular request, I made 227 compatible with UGold.Cannot join in 226f servers.If everyone upgrades to 227, there will be no fragmentation at all. I don't know why people see past that.
with a 227 client you can join older servers anyway :p
Who would run a 226f server anyway? Its replication is a complete mess...