Setting security permissions to post a Purchase Order - impossible??

Hi all

I am trying to setup security permissions to enable users to post Purchase Orders. I have most of it done correctly I believe.

For the final step, I need to give the user group Create access to the Items table (ProjItemTrans) in Projects module. I know this as I keep getting the following error message, when trying to post a Purchase Order with someone in that user group:

User is not authorised to insert a record in table ‘PROJITEMTRANS’. Request denied.

I have gone to the table to give the appropriate access but am only able to give upto Edit access, the higher access levels are greyed out! How is this possible? I dont understand how we need to give Create access but the Create access level is not available to select! Does anyone else know about this, is it a recognised issue, or do we have some weird bug in the software??? I am VERY confused…

Oh and I have the same problem with posting timesheets and project invoices too, I need to give Create access to the Hours table (ProjEmplTrans) and Fee table (ProjRevenueTrans) in Projects module, but can only select upto Edit access!!??? Has anyone managed to figure out what is going on??

Thanks for any and all help!!