If you are signed in, you aren't doing anything wrong. Sometimes there is a bit of a delay (server/bandwidth issues and all that), but eventually the flower should change to grey and the number by it increase. I hope that it starts working for you! I've sent you a flower too. =]
Sewnice, as far as I understand things it has nothing to do with your pop up blocker, so you can enable that again if you like. Were you signed in to the site before you clicked on the flower, check the top left of the page to make sure. Hope this helps, we can’t have you not being able to send flowers to people, I love sending flowers and send them to everyone, in fact I’ve sent one to you. Thanks for your question, if signing in doesn’t help let us know, thanks.