asp.net - Oracle Dual vs Sys.Dual -

i using oracle end asp.net project. have user named test. sequence worked fine (select seq_name.nextval dual;) cannot access dual directly (the sequence work when select seq_name.nextval sys.dual.so have use sys.dual. caused function ora_aspnet_createuser function (asp.net membership) become invalid since guess uses dual rather sys.dual.

any clues?