If you want use Cat 6, you must also use everything for Cat 6 - from patch panels, to wall sockets, etc. Everything is more expensive, and for GLAN is Cat5E perfectly sufficient.
Older FW don't work for new cam. I have also new cam - from 01/2015 with 5.2.8 on cam (but inside 5.2.3). And I flashed via TFTP many FW, but only 5.2.5 works perfectly. But there is no problem, with flashing via TFTP.
Here is 5.2.5 firmware:
http://www.ipcamtalk.com/showthread.php?1784-Hikvision-2532F-IS-not-getting-any-audio-through&p=20608&viewfull=1#post20608
With this file and with FTFP I flashed my cam. It works perfectly, but in Chineese.