Hi Fabrizio,
Thanks for getting in touch. However, this forum is for Pre-Sales questions only, and is not for support questions.
I’m not familiar with the plugin you mention, but it definitely sounds like there is a conflict there. I suggest that you get in touch with the developer and see if they can shed some light on the issue.
You can try posting your issue to the open source forum. We hit that forum about once a week as we can, since our core effort is on the premium forums. You might also check to see if a user has posted in the premium forums regarding a similar issue.
Best,
Leah