I open a ticket about 18 hours ago and i dont have any asnwer yet, can anyone tellme the reason?

They have up to 48 hours to reply to it, and if it isn't critical it won't be checked as urgently. Give them some time, there are probably a lot of tickets waiting to be answered.

...and, it's Thanksgiving weekend. ;)

Yea i think they mailed about their billing team and tech will be less durring the thanksgiving weekend so thats also 1 reason why ticket is taking long time to reply becuse of less staff at IPB :)

As above, it may take a little while longer than usual during the holiday period, however it is still very well within the SLA. :) , very few will take anything like that long from what I understand.

The ticket system is staffed 24/7 for support.

As an extra note: If your ticket requires management / billing attention or escalating to advanced support then it will take a little bit longer as these departments are Mon-Fri usually only.

Please check the support SLA terms that are valid for your license type: http://www.invisionpower.com/products/board/purchase.php