hallo garystampa, try this: enter about:config into the firefox location bar (confirm the info message in case it shows up) & search for the preference starting with network.http.... - please make sure that they are all set to their default values (=not shown in bold) & otherwise right-click and reset such entries.

That fixed it, thank you. I did not change that option. All I did was upgrade Firefox through its "check for upgrades" feature.

no problem, probably some sort of (ill-functioning) speed tuning programs or addons might have caused this change in the past - it is interfering with sites that use the new spdy protocol.