Warehouse is version 0.1.6 so should be current.

From command line I get an error that Aegis is preventing the install...

...which must mean that (after I had to flash my N9 a couple of days ago) I must have forgotten to allow application installs from other sources than Store...

...and this is indeed the case (strangely I could install for example Jaffa's Attitude app without any problems)...

...yet, after allowing the installations from untrusted sources I still get the same error in Warehouse...

...and after rebooting the N9 problem still persists in Warehouse. In terminal I get the same error (Aegis rejecting the install because package origin cannot be determined and signature check is failed).