Hello Penny
In the instance where the cheque number is greyed out there is a way to get the cheque number to show. If you go to accounting>chart of accounts>account history on your bank account>below date there is an add cheque (it may be set to add deposit or another transaction type) but if you click on the drop down and change it to add cheque>fill in the cheuqe number and details of the cheque (you can do a dummy cheque)save>click back onto the transaction line once saved and it will give you an option to delete.
Then go to the+ and then cheque and the cheque number should no longer be greyed out.
Any issues let us know
Thanks
Emma