What is the best software for managing eBay listings?
 

For those of you who regularly sell items on eBay, which software do you use to manage your listings?

I have been using Sixbit for several years. It is great for listing items but it is buggy when it comes to creating invoices. If a buyer has won several items over a course of several days, for some reason Sixbit does not pick up all the items when I create an invoice. This happens every single night that I have to create new invoices. I have to then retrieve each item individually that is missing. This becomes time consuming and defeats the whole purpose of using software to create invoices.

I have spoken with Sixbit several times and they have never been able to correct the problem.
I am now ready to move away from Sixbit and start using a different service. But, which one should I use?

I would love to hear your suggestions.