menu buttons in KM menu and context menu not working in firefox 33.0

Hi,

in our Portal (NW 7.4 SP07) the KM menu buttons and context menus in KM navigation iViews don't work when using firefox 33 (with IE and Chrome it works). In console we get the following error:

TypeError: rows is not a function sapUrMapi_ie6.js:12272

ReferenceError: event is not defined sapUrMapi_ie6.js:833

Is "sapUrMapi_ie6.js" the right js-File here for Firefox?

Any suggestions?

Regards,

Golo