Hi, Recently, when i was browsing through one of the axpata site, I found this article which caused blocking in SalesTable and SalesLine tables when concurrent users try to update Sales Orders. This is noticed in sales order update processes that use the salesFormLetter class and invoke credit checking during the update the checkSales method of the salesFormLetter class places multiple tables in a transaction state while it reads their data. This blocking issue is most severe if the client has invoicing accounts with multiple associated customer accounts and a substantial amount of uninvoiced orders. Fix: Modify salesFormLetter::checkSales comment out line 6 and line 21 in the unmodified sys layer code, this removes the ttsBegin and ttsCommit from the checksales, since the process this method performs is read only there is no real need for TTS during the operation.