I have an iMac using OS 10.7.5. This morning I attempted to install two current updates - one relating to iTunes, the other to a Canon printer I installed for the first time earlier in the week. Having begun the process I received a message to say the update could not proceed because "The 'System/Library/Extensions/AppleUSBEthernetHost.kext' file was installed improperly and cannot be used. Please try reinstalling it or contact the product vendor for an update" It was installed and last opened in January 2012 and doesn't seem to have caused a problem before. What am I meant to do? Incidentally the two updates were installed without any further comment, it would seem!