Hy Guys,
I use two wp 3.5.1 platform with CF7 3.3.3 plugin on the same server, cf7 was working on one platform but not on the second.
On the wp platform where the cf7 wasn t working, I ve created a new cf7 with all the configuration needed before saving it as a new cf7 and it works now.
For some reason, it seems that if you modify your cf7 after creating it, it will not work anymore.
I did not fix the plugin issue, but at least I can work with it.
Hope it can help !