I think that the bug was misunderstood. I have noticed the same bug but when I scaled the UI the other way -- down.
In "System Settings > Displays > Scale for menu and title bars" I set 0.875 to have smaller control elements in the GUI. This setting also scaled the fonts down. Unfortunately few days later I noticed that the fonts are very small - almost unreadable. I did not have Unity Tweak installed at this time so it is not certainly a bug on the Unity Tweak Tool. Returning the "Scale for menu and title bars" parameter back to 1 did not return the scaling to normal. To quickly check various parameters inaccessible in the standard UI I have later installed Unity Tweak and there I noticed that the scaling factor for fonts was set to 0.5. I have never configured the scaling factor for fonts! After returning both scaling factors to 1 the system appears normally again. ** Changed in: unity (Ubuntu) Status: Invalid => New -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to unity in Ubuntu. Matching subscriptions: dp-unity https://bugs.launchpad.net/bugs/1317253 Title: UI scaling and font scaling sometime get confused/change at random. Status in Unity Tweak Tool: New Status in “unity” package in Ubuntu: New Bug description: I have a Lenovo Yoga 2 Pro, with a 13.3" screen running at 3200x1800 pixels... I bought this partly to test out the UI scaling in Unity!... and I have to say it's very awesome (both the screen and the UI scaling)... however I have encountered a strange problem. Seemingly at random, I have so far 3 times in 10 days had the font size (not UI size) suddenly jump to something much too large. UI scaling for the display is set at 1.38x and this is quite perfect for me, it sure means no one will be able to read my screen over my shoulder, but I that's fine! I had to install a Firefox plugin to apply scaling there, but I realise why that is. Anyway... I installed ubuntu-tweak and discovered that the large fonts were due to the "Text Scaling Factor" having jumped up to a number above 2.5... I also discovered that I could not move the slider because every time I moved it the fonts re-scaled the slider moved and lost mouse focus... and the slider reset to where it was to begin with... I clicked the button on the right to return to 1.0, and it returned to 1.4, which I assume is representative of the 1.38 I set in the screen scaling... but I have no explanation for why it suddenly jumped (when I logged out and back in) from 1.4 to something like 2.5.).. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: unity 7.2.0+14.04.20140423-0ubuntu1.2 ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CurrentDesktop: Unity Date: Wed May 7 20:55:53 2014 EcryptfsInUse: Yes InstallationDate: Installed on 2014-04-28 (8 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) SourcePackage: unity UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/unity-tweak-tool/+bug/1317253/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp