A BUG when trying to close the left sidebar. Puntuado con 4 de 5 estrellas

I have Firefox 20 and, even in earlier versions, I noticed that sometimes I could not close the left sidebar when it had been opened following a download when I clicked on the X at the top right to close it.
The only way I could see it closed was to close Firefox and restart it from scratch.

I usually have many tabs opened but I also have 8 GB of RAM and more than half is usually not even on use.

Please, solve this BUG.

Many thanks to the developer because I find this addon indispensable.

Esta valoración es de una versión anterior del complemento (0.9.7).