I don't know how SSO works so can't suggest a solution.
However the cause is that the oraclemaps.js is not accessible.
i.e. the BI dashboard page (with a map view) is requesting the file
/mapviewer/fsmc/jslib/oraclemaps.js and that is not accessible.
I have no clue why this happens with SSO but not without SSO.
Someone in the OBIEE forum might however.