Not a bad list of installed softwares. You have a slightly older Java version installed, so when you can go
here and download the latest version of Sun Java
Java Runtime Environment (JRE) JRE 6 Update 16. Be sure the version you choose matches your system there. Download the offline installer, run it then reboot after. It should remove the older version as part of the install.
If I were to look to a culprit for this online issues, I would wonder about that Windows Media Player Firefox Plugin. How long have you have that installed there?