Whatsapp does not show a contact. Tried "everything" I have an Xperia Z1 with Android 4.2.2 and the latest version of Whatsapp.
There is at least one contact whom I am sure has got Whatsapp but is not shown in Whatsapp contacts.

The contact is in my phone's address book, with country code.
"Show all contacts" is selected, no hidden contact, auto sync is on; I manually synced, refreshed, deleted and reinstalled both contacts and app.

Other ideas?
Some options you could try:

Option 1

Tap on  icon and then go to  Menu &gt; Refresh.

Option 2

Tap on  icon and then go to  Menu &gt; Help. There are some instructions their which you can try and tap on Show invisible contacts.

Option 3

Follow this article from WhatsApp to try to troubleshoot: How do I add contacts to WhatsApp?