Hi there !
It take me a lot of time and a bunch of test but i found something strange.
Some users were complaining about uncomplete registration validation email.
As i was on PC and my tiki acces was english i couldn't find what was wrong.
Now i can say that for unnkown reason, when a user is using a Macintosh on my site (french by default) the validation email is cut.
I have tried to get rid of accent (french way to keep being original ) on language.php but then i saw ascii caraters instead of the accent letter.
Anyway it didn't solve the problem.
Who want more information ?
What test do you want me to conduct ?