Wierd Firefox Errors

Every once in a while I get fed up with Firefox and switch to Konqueror, only to return a few days later. The latest annoyance with ff is an old one; when you type in a text into the search box, an error pops up.

ASSERT: *** Search: _installLocation: engine has no file! Stack Trace: 0:ENSURE_WARN(false,_installLocation: engine has no file!,2147500037) 1:() 2:() 3:SRCH_ENG_getSubmission(wad,application/x-suggestions+json) 4:getSubmission(wad,application/x-suggestions+json) 5:(wad,searchbar-history,null,[xpconnect wrapped nsIAutoCompleteObserver]) Fortunately it's not very serious and can be made to go away by just restarting FF. On this occasion, I was too lazy to do even that and continued with my work until some JavaScript started to misbehave. Then I tried to view source, only to run into this error:

XML Parsing Error: undefined entity Location: chrome://global/content/viewSource.xul Line Number6, Column 1:<window id="viewSource"

This time though, I am not going to switch back to Konqueror, cause I know that the culprit here isn't Firefox but yum!. That's right, you see this sort of error most often when the system has been updated. When firefox is updated it has to be restarted but when you do the update with yum it doesn't happen automatically.