Before marking this as a duplicate please read my question throughly.
OK I am having a bit of a problem with Gnome Shell (3.3.90); Any time there are any icons in the bottom notification bar it causes massive lag when opening/closing and interacting with the Activities panel. If I close all applications that have a notification icon the lag goes away 100%. In My case it's drop box, but any program that requires a icon in the notification area will cause this issue to happen.
I am using an AMD A6-3420M running Catalyst 11.11, however I can confirm that this is not a driver issue. I had the same issue on a system running a GeForce 8600GT,and a HD6850, and there is another question on here titled "Gnome Shell lags after a while" where the user is having the same exact issue and He is also using a nVidia card, a 9800GT to be specific.
Please, this question has been asked several time and every time people say its a fglrx issue and close the question, or they mark the question as a duplicate and link to a question that says its an fglrx issue. This is not a driver issue, I understand that the AMD drivers caught heat for quite some time for Gnome Shell compatibility issues but those issues have been resolved. Aside from this issue Gnome Shell runs beautiful on my HD650, my A6-3420M, and my 8600GT.
Having said that, does anyone know how to correct this issue? Closing Drop Box is not an option for me either.