Then when I again enable System - Jfrouter, sitename is correct in English but the links no longer work.

When I use JoomSEF with JoomFish all works fine except for one. All pages of the second language version sitename in the title bar is displayed in the base site language, that is one that is recorded in global settings joomla.

System - ARTIO JoomSEF -- is enabled.
System - Jfrouter -- is disabled.

It appears that the plugin System - ARTIO JoomSEF is not get translated sitename from jos_languages