Installed desktop version is from the zdesktop_2_0_1_b10659_win32.msi release.

I have tried various GMail contract exports and despite the 'success' notification that Zimbra dispalys not one contact is uploaded.

From GMail:
I have tried csv, google and vCard exports.

Into Zimbra:
Auto-Detect
Outlook
Outlook 2003 contacts have been tried.