Problem with App store after updating to Mavericks
I have just updated to Mavericks and now can't access the App store properly. I can access the iTunes store with my AppleID and download apps from there and somehow I managed to update iTunes and some printer software through the App store but I can't sign in to see my purchases and I can't purchase anything. I've tried deleting NetworkInterfaces.plist from the library as suggested somewhere else; I've restarted my Mac twice.
I don't much fancy trying to reinstall Mavericks as it took about 6 hours to download to start with (v slow broadband!) and presumably since I can't purchase anything from the App store I won't be able to do that anyway!
I really hope someone can help, particularly as I was wanting to purchase something which is only on offer until midnight!!
Thanks in anticipation...
OS X Mavericks (10.9)