When a USB camera is connected font hinting setting is not respected (e.g. slight vs. full)

If a USB camera is connected , then after booting the system not working hotkeys not defined web camera and some applications (for ex. Nautilus) have corrupted font hinting.After about 30 seconds is determined by the webcam and start working hotkeys. They are also not affected on changing font settings (see attached screenshots).
If Nautilus is running as root - fonts are normal (screenshot). Sometimes browsers such as Google Chrome, Firefox etc. are also affected.
With other web cameras and USB devices problem does not appear. Webcam because of which there are errors A4tech model: PK-5G . There may be other brand.
Webcam in lsusb: ID 0ac8:3420 Z-Star Microelectronics Corp. Venus USB2.0 Camera
Appearance of this applications can be set to normal:

- after the screen will blink for approximately 30 seconds;
- after closing user session and login back;
- after closing nautilus with "nautilus -q" for 1-2 times and entering the command compz --replace in the terminal.

/home folder is formatted before install, so no settings can not affect on appearance for this applications.

This problem is actual for Trusty Utopic and Vivid with the latest updates.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-3.18.0-13-generic 3.18.0-13.14 [modified: boot/vmlinuz-3.18.0-13-generic]
ProcVersionSignature: Ubuntu 3.18.0-13.14-generic 3.18.5
Uname: Linux 3.18.0-13-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.16.1-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: lebedev 1765 F.... pulseaudio
 /dev/snd/controlC0: lebedev 1765 F.... pulseaudio
CurrentDesktop: Unity
Date: Thu Feb 26 20:40:55 2015
HibernationDevice: RESUME=UUID=35a01c20-45a3-4982-b507-3188231aded0
InstallationDate: Installed on 2015-02-25 (1 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150224)
IwConfig:
 eth0 no wireless extensions.

 lo no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. GA-MA74GM-S2H
ProcEnviron:
 LANGUAGE=ru
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=ru_RU.UTF-8
 SHELL=/bin/bash
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.18.0-13-generic root=UUID=6a594b10-f93b-468f-ba5b-a6a4381aed3b ro quiet splash
RelatedPackageVersions:
 linux-restricted-modules-3.18.0-13-generic N/A
 linux-backports-modules-3.18.0-13-generic N/A
 linux-firmware 1.141
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/19/2009
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F4b
dmi.board.name: GA-MA74GM-S2H
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF4b:bd11/19/2009:svnGigabyteTechnologyCo.,Ltd.:pnGA-MA74GM-S2H:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-MA74GM-S2H:rvr:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: GA-MA74GM-S2H
dmi.sys.vendor: Gigabyte Technology Co., Ltd.