Too many instances of processes left running in 64 bit version

$ uname -a
Linux ajsc855 3.13.0-46-generic #76-Ubuntu SMP Thu Feb 26 18:52:13 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.2 LTS"

Hardware is a Toshiba C655 i3 laptop with 4GB ram and 500GB HD.

I typically run Thunderbird, Firefox, a terminal or two, Gthumb, Gimp, Qcad, Gedit, Libreoffice, Inkscape, Document Viewer and occasionally Virtualbox.

It seems to me that there are quite a few extra copies of some processes populating memory after running a session for a few days. Namely, dbus-daemon, gvfsd and gconfd-2. The more I use the session, the more of these processes appear. After a while they start using up a significant amount of memory and system response seems to slow down.

Logging out and back in did not alleviate the problem. Rebooting did.

The example session used to get the following results was probably well over a week in use.

Before rebooting:
$ ps -ef >prereboot.txt
$ grep -i dbus-daemon <prereboot.txt|wc -l
40
$ grep -i gvfsd <prereboot.txt|wc -l
78
$ grep -i gconfd-2 <prereboot.txt|wc -l
37

After rebooting:
$ ps -ef >postreboot.txt
$ grep -i dbus-daemon <postreboot.txt|wc -l
4
$ grep -i gvfsd <postreboot.txt|wc -l
5
$ grep -i gconfd-2 <postreboot.txt|wc -l
1

I am at a loss as to what is causing this.

--Alex