roles and transaction logging

Hi guyz, Transaction logging and roles seems to be like oil and water. For one I've found out that you cannot issue a set role command within a transaction block (in informix 4gl). So to overcome this i issue my set role statement then I issue my begin work statement. This works fine except that the user still cannot insert into the table. I've granted permissions to the role and I've assigned the user to the role. What am i doing wrong? And why can't you issue a set role statement within a transaction block? austin