The changes of the 1.2.1.0 update are:
ChangelogBug Fixes* Fixed missing Bergetiger.
* Fixed Sherman 105 Bulldozer/MG upgrades use same slots.
* Fixed Sherman 105 didn't have "Lower Bulldoze" ability.
* Fixed Jagdpanzer IV vetrency requirements.
* Fixed missing smoke on Strafe run.
* Fixed missing name of the Jackson when mousing over it.
* Fixed that GWagen MG didn't require Vet 2.
* Fixed Comet driving through objects.
You can easily check if the patch is applied by trying to get one of those bugs. Also, do you have CoH on Steam?
Changelog 1.21