Yup, my latest solution was that I created a new business and start all over again from 0 invoice, 0 item.
It also lagging on the actual program. Deleting cookies doesn't affect anything.
For the record I use SSD for the server, 8G of RAM
Just updated to 7.25
After years struggling with the slow on every part, I thought latest version would be a nice way out. And I found out that it is not, adding ONE item in new invoice still takes minutes [by browser - I use chrome].
This is truly a total disappointment. Just burn out my $79.99 :D