Gmail/Google Reader Unexplainably Slow/unresponsive in Firefox

Today my Firefox started behaving very strangely and extremely slow especially when using Gmail and Google Reader. I tried cleaning the cache, restarting but nothing solved. Then, I realized I had installed Skype these days and it installed a Firefox add-on without even asking me for permission. I removed the add-on and Firefox went back to normal operation, fast and reliable, as always.

I have to say that Skype dissappointed me this time installing a defective add-on on my browser, since I don’t even remember to have allowed it to do so.

Seems like I wasn’t the only one who had this problem. :(