Can't set Calculator key to show/hide Tilda

[Alexander]

After installing Ubuntu 14.04 beta a week ago I installed Tilda. At first it worked fine with Calculator key on my keyboard, but later it began telling me I can't use it as a shortcut for showing/hiding Tilda.
A screenshot is attached to demonstrate the problem.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: tilda 1.1.11-1
ProcVersionSignature: Ubuntu 3.13.0-19.39-generic 3.13.6
Uname: Linux 3.13.0-19-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Mar 23 15:42:53 2014
InstallationDate: Installed on 2014-03-18 (4 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140316)
SourcePackage: tilda
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastian Geiger (lanoxx)]

This is most likely not a bug in tilda. Probably Ubuntu prevents tilda somehow from grabbing that key, in that case there is not much I can do. You can check if any other application on your system is blocking that key.