URIの正規表現用文字列にtypoがあります。

Index: lib/uri/common.rb
===================================================================
--- lib/uri/common.rb   (revision 14176)
+++ lib/uri/common.rb   (working copy)
@@ -110,7 +110,7 @@
       SERVER = "(?:#{USERINFO}@)?#{HOSTPORT}"
       # reg_name      = 1*( unreserved | escaped | "$" | "," |
       #                     ";" | ":" | "@" | "&" | "=" | "+" )
-      REG_NAME = "(?:[#{UNRESERVED}$,;+@&=+]|#{ESCAPED})+"
+      REG_NAME = "(?:[#{UNRESERVED}$,;:@&=+]|#{ESCAPED})+"
       # authority     = server | reg_name
       AUTHORITY = "(?:#{SERVER}|#{REG_NAME})"

-- 
上田智 <s-ueda livedoor.jp>