Cannot set 2560x1440 (maximum is 2048x1080) on Geforce GT525M

I’m trying to set my monitor (DELL UP2516D), connected to my laptop’s Geforce GT525M (driver version 367.35) via a high quality HDMI cable, to its native display resolution of 2560x1440@60 Hz but the only resolution offered is 2048x1080. I tried forcing it via several means described on the net (nvidia-settings --assign, xrander --addmode, adding Modeline to xorg.conf), to no avail.
Both, the GPU specs and the monitor’s specs suggest it should be possible.

What could I do to get that working?

Edit:

I got this error message when trying to use xrandr:

> xrandr --newmode "2560x1440"  241.50  2560 2608 2640
2720  1440 1443 1448 1481 +hsync -vsync

> xrandr --addmode HDMI-0 2560x1440
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  18 (RRAddOutputMode)
  Serial number of failed request:  27
  Current serial number in output stream:  28

After digging some more, I found this statement from DELL:
“A maximum resolution of 2048x1152 through the U2515H HDMI in means that the signal it is getting from the video card is not HDMI 1.4. It is HDMI 1.3. Which is why you are getting 2048x1152. The other user got a 2015 video card and its HDMI was 1.4, so he could do 2560x1440.”
Source: http://en.community.dell.com/support-forums/peripherals/f/3529/t/19641517

Well, I have a different monitor and a different maximum resolution but could it be that the GT525M in my laptop is not providing an HDMI 1.4 compliant signal? If so, is this a hardware limitation or a limitation in the driver? It says here that the chip can do 2560x1600, albeit via DVI. I’m confused…
nvidia-bug-report.log.gz (104 KB)