SQL & PL/SQL

Hi,
I know it's an Oracle Forum and not a TOAD one but the company firewall won't let me at the TOAD forums so apologies first off.

I have to "set role plustrace" before "set autotrace on" in one of our schemas. This works fine in SQLPLUS and also when I run a query as a script in TOAD. But when I try and use the data grid and set autotrace on it tells me I don't have access to v$session.
In another schema where I don't have to set the role it works fine.
I'm using the Oracle plan table and not the TOAD one.

If anyone had any ideas that would be great.