Such a simple function, i'm actually quite amazed it's not already a feature. It would be great to see an option (possibly in the "Invoice Defaults" screen) whereby you can tick a box to allow newly created invoices/credits to automatically update customer ledgers, rather than having to manually select each invoice or a run of invoices and click that annoying "update ledgers" button and generate an arbitrary/useless report.

I can understand why automatically updating might not be suitable in some circumstances, which is why i suggest this should be an optional tick-box setting.