Temperature Fluctuation in MD simulation with MS8.0

Hi,
We have recently bought MS version 8 and I am working with MS8.0 to do molecular dynamics simulation of clay minerals by CLAYFF. previously I was working with MS version 5.0 and from Accelerys community I found that it is not compatible with CLAYFF, so I have upgraded it to the latest version however the problem is not soved. The description of my work and problem is as follows:

I am working on kaolinite. 
1. Give the kaolinite structure from materials studio library and build a supercell (2*2*3)
2. Cleave (001) surface
3.Build vacuum slab
4.Run geometry optimization by CLAYFF
5. Run molicular dynamics simulation in Forcite by CLAYFF in NVT ensemble at 298K for 100 ps to relax the structure
and I choose random velocity but the temperature goes very high and fluctuate significantly resulting in the structure changes due to the high tempearature. I have tried all termostate (Nose, Andersen, Berendsen)  but nothing changes. Could you please help me to solve this problem?
Thankyou