hi everybody i'm new to LM after years of fedora-ubuntu

but...
i've got the same freezing prob with LM 14 Cinnamon 1.6.7 running on
dell m4500
cpu Intel® Core™ i7 CPU M 640 @ 2.80GHz × 4
graphics Gallium 0.4 on NVA3
( lspci -> 01:00.0 VGA compatible controller: NVIDIA Corporation GT215 [Quadro FX 1800M] (rev a2) )
os 64-bit
but not 
same LM 14 on acer aspire 5552G !!
amd Athlon II P320 dual core
graphics Gallium 0.4 on AMD CEDAR
os 64-bit
it happens when libreoffice it's running (at least i think that two events are linked... )
ther's an error in syslog (dnsmasq)
*****
NetworkManager[935]: <error> [1356804777.987259] [nm-dns-dnsmasq.c:390] update(): dnsmasq not available on the bus, can't update servers.
*****
in .xsession-errors
****
(gnome-settings-daemon:1820): libappindicator-CRITICAL **: app_indicator_set_label: assertion `IS_APP_INDICATOR (self)' failed
(gnome-settings-daemon:1820): libappindicator-CRITICAL **: app_indicator_set_label: assertion `IS_APP_INDICATOR (self)' failed
****
thanks in advance for your advice

p.s. i've installed nvidia drivers (what a dumb, i've forgotten ) !!! at the moment all work fine (libroffice open and running) but i wait a little bit to say solved
Partially solvedSometimes my mintbox freeze but not so often (four times in a week) after i've installed nvidia drivers
the last freezing experience was with "Inkscape"