The problem is the redirect in the cache file:

YUI( YUI3_config ).add('io-ez', function( Y )
{
    var _rootUrl = '/siteaccess1/', _serverUrl = _rootUrl + 'ezjscore/', _seperator = '@SEPERATOR$', _configBak;
...
..
.

If we load domain/siteaccess1 everything is correct, but with domain/siteaccess2 we have a redirect to domain/siteaccess1

In this patch I add the siteaccess into the generating the cache_path.