Sales Invoices number sequence out of sync

This issue has flawed me as it's never happened before. As we have more than one person working on the software at the same time we're noticed that if one person has started entering a quote or order and has a selected number and another is working on another recorded quote when the person is about to save their new quote it takes up the already recorded quote number that the other person has been working on and doesn't warn that it's a duplicate. Not sure why it's not just keeping the number that was already entered. The only way we have noticed the change of number is when we either email or print out the quote.

This is also happening when dealing with purchase orders. If two people are working on two separate purchase orders - one being raised and one already recorded the one being raised with divert to the already recorded number and not keep the number already in the sequence.

I really need help with this as we are getting duplicate numbers and some really frustrated staff members.

It's enough with the already **bleep**py work arounds we have to deal with in MYOB - this is just beyond comprehension. MYOB is meant to be able to cope with multiple users - hopefully this is not yet another issue that MYOB has overlooked for its new and improved programs.