According to the site admins, 99% of problems get resolved by deleting cookies and clearing the browser cache of downloaded temporary files.
So please go ahead and try that. You obviously only have to delete cookies from PPRUNE and IB.
Do you have NoScript and / or AdBlock running? Over-zealous use of these can block necessary stuff from the PPRuNe site. You CAN block ibpxl.com, but you CANNOT block ibsrv.net without severe loss of functionality.
SD