SSL support and white square behind menu

Hello.
I’m running SSL on my site, so I’ wondering if it’s possible to load the Spreadshirt images through SSL?

I also have a problem with a white square behind the menu. (Transparent menu)
If I remove the Speadshirt plugin from the page the square is gone.
Here is an image of the white square.
IMAGE

Help much appreciated! ??

https://www.ads-software.com/plugins/wp-spreadplugin/