I get the following error with geoext in Firefox (and Chrome fails as well). I have updated to ext 3.4.0 and get the same error.
It is loading a datagrid using geoext. Works fine in IE (for a change!).
Error: uncaught exception: [Exception... "Failure" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: http://myhost/dev/ext/ext-all.js :: <TOP_LEVEL> :: line 11" data: no]