The Pantheon was frozen while multitasking

[Szander]

There was a problem while multitasking. To tell you the truth, i tried Ubuntu 1404 and it was the same problem: the desktop environment was frozen.
The HDD started to loading something without end, I had to push the restart button on my machine.

ProblemType: Bug
DistroRelease: elementary OS 0.3
Package: elementary-desktop 1.350+394~ubuntu0.3.1 [origin: LP-PPA-elementary-os-daily]
ProcVersionSignature: Ubuntu 3.13.0-34.60-generic 3.13.11.4
Uname: Linux 3.13.0-34-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.3
Architecture: amd64
CrashDB: elementary_meta
CurrentDesktop: Pantheon
Date: Tue Aug 26 16:50:23 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-08-24 (1 days ago)
InstallationMedia: elementary OS 0.3 "Freya" - Daily amd64 (20140810)
ProcEnviron:
 LANGUAGE=hu
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=hu_HU.UTF-8
 SHELL=/bin/bash
SourcePackage: elementary-meta
SuspiciousXErrors:

ThirdParty: True
UpgradeStatus: No upgrade log present (probably fresh install)