Safari problem

There was some sort of security patch for OS-X last night. Today I can't get the tab bar to work properly in Safari, if I open a second tab I lose the first and have to use "show all tabs" button to show them all, which is a lot less convenient. Anyone else come across this?

later - this seems to have partially cleared after a couple of reboots - I've got the tabs back, but for some reason I'm still seeing the URLS of all of the open tabs overlaid in the address box, or the same one showing twice overlaying itself, and searching from the address box doesn't work. VERY strange.