Mouse button hold lags sometimes

I am using a synaptics touchpad, so when I say mouse you know what I mean.

As the title says: say I want to move a window via the titlebar or that I want to select some text, I hold the first button and without a care in the world start moving the mouse to drag/sectect. The problem is the mouse hold isn't detected on time, I end up moving the mouse pointer without any effect. Then one or two seconds later the mouse button hold is dispatched and I end up selecting the wrong text or clicking outside the titlebar.

This bug manifests sometimes when I log in, and is kind of erratic even inside the session (but quite persistent during the session).

Notice that while the bug manifests: a simple mouse click works (left or right), a double click also works, and the mouse wheel/third button works too.

After logging out and logging back in, the bug vanished. Please understand that this bug has happened to me at least three times. I have gnome-shell installed (but the bug had presented while using Unity).

*What is expected to happen*
That the dragging/selection interaction is started as soon as I hold the mouse button and there's no evident/unacceptable delay.

*What happens*
When I hold the first button of the mouse, I get no response for a second or two (tops): the text is not selected if I move the mouse, the titlebar is not 'grabbed' by the little hand so I can move its window (and other use cases are possible to have the same problem).

Description: Ubuntu 13.04
Release: 13.04

compiz:
  Installed: 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
  Candidate: 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
  Version table:
 *** 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1 0
        500 http://do.archive.ubuntu.com/ubuntu/ raring/main i386 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-26.38-generic 3.8.13.2
Uname: Linux 3.8.0-26-generic i686
.tmp.unity.support.test.0:

ApportVersion: 2.9.2-0ubuntu8.1
Architecture: i386
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Thu Jul 11 08:52:39 2013
DistUpgraded: Fresh install
DistroCodename: raring
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 4.2.10, 3.8.0-25-generic, i686: installed
 virtualbox, 4.2.10, 3.8.0-26-generic, i686: installed
GraphicsCard:
 Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:30a2]
   Subsystem: Hewlett-Packard Company Device [103c:30a2]
InstallationDate: Installed on 2013-04-26 (75 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
MachineType: Hewlett-Packard HP Compaq nx7400 (GF451LA#ABM)
MarkForUpload: True
PackageArchitecture: all
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.8.0-26-generic root=UUID=d2b3b60a-c467-487e-a35f-e7405c607091 ro quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/18/2006
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68YGU Ver. F.0A
dmi.board.name: 30A2
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 40.17
dmi.chassis.asset.tag: CNU7111JLR
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68YGUVer.F.0A:bd12/18/2006:svnHewlett-Packard:pnHPCompaqnx7400(GF451LA#ABM):pvrF.0A:rvnHewlett-Packard:rn30A2:rvrKBCVersion40.17:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP Compaq nx7400 (GF451LA#ABM)
dmi.product.version: F.0A
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
version.libdrm2: libdrm2 2.4.43-0ubuntu1.1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.1.3-0ubuntu0.3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.1.3-0ubuntu0.3
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3-0ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.6-0ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.7-0ubuntu1
xserver.bootTime: Thu Jul 11 12:48:15 2013
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.3-0ubuntu6
xserver.video_driver: intel