Happy to hear that you like it and thanks for taking time to write a review and rate Custom Sidebars, we really appreciate that 🙂
With regards to your issue I’ve tested this on my sandbox site and I couldn’t recreate the issue, I’ve managed to add multiple widgets of the same kind without any issues http://screencast.com/t/081i3KauVvj.
If you’d like you could open a support ticket so we can try to troubleshoot this 🙂
Cheers,
Bojan