The fire in my 4th tribe doesn't know that I'm in Fast Speed!!
As Tufi is nursing for 123min and the banana tree will produce fruit in 3h 53 min!! and my villagers become older of 1 year in 1 hour
The 3 other tribes are running in Slow Speed and were in slow speed when I started the 4th! But I'm sure that in the Options this 4th is in Fast!
It' not really annoying except that I wonder what will happen for the diamond!

That's a well-documented glitch caused by repeated pausing. If you put wood on the fire, it will return to normal. You can see a very detailed report earlier in this thread.

Well I though about repeated pausing could make the problem! But it's so tempting when you have 3 kids and a lovely red mushie!!
Thanks a lot! it's now returned to normal!

i have a problem. my fire has been out for 2 weeks and its been on fast speed the whole time and i cant seem to get the ash key

You have to keep the fire burning continuously long enough to generate the key (at least several days). Leaving it out for 2 weeks won't produce the key.