Steam problems after latest update!

Hi guys,

Ever since I installed the latest Steam update (the one that came out this Monday) I cannot visit my profile, the store or any other web-related section from within Steam client.

I can only see the library and the chat and when I try to access another section I get Error Code 7/138 - Unknown Error.
Also, I cannot install/uninstall games and the restore backu function does not work (same goes for copying the game folder from one PC to mine).

The in-game browser does not work as well. Oh, and it takes like 30 minutes or more to for Steam to sign in.

This happens on 2 systems. On my laptop, right after the update got installed I got an Internet connection error and I can no longer sign in.

I already created a support ticked and tried to get in touch with them on Tweeter & Facebook (as far as I could see I'm not the only one with this problem) but so far no answer.

Is anyone of you guys experiencing or has encountered this issue? Any ideas on how to solve it?
I already tried flushing the configuration files and forced a new client update as well as an fix/install over. Nothing helped.