Tried to open Yahoo mail - got message saying this version of Firefox does not support the latest Yahoo mail - update or use older version with limited functions in mail. Updated Firefox browser via link provided - installed - started browser - Home page opens OK - click new tab - try to open mail - new tab appears with black dot moving left / right but nothing else happens - whatever web site I try to open will not open in a new tab - but using the tab which opened with home page on - all websites open ok. Effectively can only have 1 tab open.