Glad to know it is not just me... :P
Regarding the nands, I have changed back to NAND 2, enabled framerate 50/60 and now it is working , as soon as I change to a US channel it goes to 60 and it goes back to 50 when going back to Stalker main menu (Home), haven't checked yet with 24. It looks like the NANDs have different compatibility issues and other thing I have noticed is that in the inner portal there are 2 or 3 apps missing on the NAND 2, not sure which ones though as I don't use any of them but quite strange nonetheless...
Update: Changed to 24/50/60 and confirmed it is switching between the 3 framerates without any issue!
Also I have made a firmware update to the same current version and after the reboot it automatically changed to NAND 1! Weird behaviour...