long columns data load thru sqlldr

Hi,
I tried to load a tables which has long column is failing always.For example i have 2 tables with long columns.

1.xx(a number,b long,c varchar2(20)
2.yy(a number,b long)

When i load the table xx,the sqlldr saying the column b should be placed last and when i load the 2nd table yy its saying column b too long.

I think i am missing something in my loader script.Can someone help me in this regard.

Thanks