Request assistance or feedback on ongoing URL alias problem: not working when non-English default language has no (empty) path prefix

Hi i18n group,

I would be extremely grateful for any input concerning the following reported i18n issue:

URL path alias for non-English default language pages only working for some web browsers

In short, the default language for the site in question (http://www.aur.no) is Norwegian Bokmal, which the client wants to appear without path prefix 'nb' for Nowegian users. When Norwegian Bokmal is set to have null (empty) path prefix all URL aliases for its nodes fail with Page Not Found error.
English is set with explicit path prefix 'en' and all URL aliases work fine. All direct access using node/nid form works fine for both languages.

This matter for a small incubating site has become extremely time-consuming so I'd be very appreciative of any feedback, especially concerning examples of functioning sites with non-English default language without path prefix.

Webel