Less duration gem not affecting Poison duration applied by Earthquake

From Patch 2.5 notes

"

Bleeding effects from non-puncture sources are now affected by the same (additive and multiplicative) duration modifiers as bleeding effects from puncture sources.
Poison from non-Viper Strike sources is now affected by multiplicative skill effect duration modifiers. Additive skill effect duration modifiers were already being applied.

Poison duration from the wiki (http://pathofexile.gamepedia.com/Poison#Duration

"

The duration can be extended by sources of increased Skill Effect Duration, such as the Increased Duration Support or the nodes in the passive skill tree.

I decided to do some testing since I have all the gear in Standard (you may check gear used for testing in my profile if you want. Char name is _Kaio_NS_)

Base poison duration: 2 secs
Expected duration with "Less Duration 20/20": 20,510,9= 0,918 sec

However, by doing a quick test at Dried Lake with Earthquake + Less Duration gem 20/20 + Poison gem (no quality) or Cospri's Will, I've noticed that Poison duration was way longer than 0,918 second (No other sources of increased/reduced skill effect duration nodes were used)

On the other hand, linking "Increased Duration" gem to Poison + EQ increased significantly increased the poison duration, just as stated on 2.5 Patch notes.

After that I did more testing, now using EQ + "30% reduced EQ duration" enchant + Rapid Dacay (15% reduced skill effect duration), and both of them reduced poison duration applied by EQ. (I actually was surprised by EQ enchant reducing poison duration... Didn't think it would)

So, basically, it seems that increased/reduced skill effect duration are working as stated in the 2.5 Patch Notes. However, less skill effect duration from Less Duration gem seems to have no effect at all over poison's duration, which is totally against to the patch note's statement.