i can't help you with your problem, but i believe that little icon you have there is the symbol for a picture about to be loaded. i'm not sure though.
I was browsing a site, which contained several pages with pdfs. When I click on the link, the window does not open the pdf. I get a little icon.
I was actually on the phone with the fellow on the web site, because he was directing me to the correct link to get the information I was looking for.
The little icon is in the upper left corner of the open window space, and has a red square, blue triangle, and a green dot, inside of 1/4" square.
When I mentioned to him that I couldn't get the window to open, he told me to clear my cookies, and delete the temp internet files, which I did.
I have Adobe Reader version 6. IE6, 768 RAM, Pavilion 9870, with 60 Gb HD, 1.3 GHz.
He said that something was wrong on my end, but I've been able to open other pdf sites just fine.
I'm also running a hardwired firewalled router, anti-virus (mcafee) and have SP2. Google pop up blocker, but ctrl doesn't do anything different.