Pandora requires the Shockwave Flash plugin, and perhaps others, to be active. I would not disable any of those plugins which you have disabled. Try enabling shockwave flash, then restarting Firefox, to see if this resolves the issue. If it does not, try enabling the rest of your plugins.

Loggerman said

Pandora has been helping me troubleshoot and just found out that I was able to register and get music with IE. Is Firefox the cause of this? The only plug-in activated is Open H264 Video Codec provided by Cisco Systems Inc. 1.3 The plug-ins that are disabled: Adobe Acrobat 11.0.8.4, Google Update 1.3.26.9, Java (TM) Platform SE7 U55 10.55.2.14, Microsoft DRM 9.0.0.4503, Quicktime 7.7.67.7.6.0, Shockwave Flash 17.0.0.169, Shockwave for Director 11.5.9.615, Silverlight 5.1.30514.0, Windows Media Player Dynamic Link Library 3.0.2.629, Windows Presentation Foundation 3.5.30729.4122. Which of these do I have to make active

Thank you Mark !!!! I am not sure how shockwave flash got turned off but turning it on gave me Pandora back.