[HELP] Currency of VM 2 with Joomla 2.5.6 don't apear exactly with Vietnam Dong?

[www.vn-boom.com]

hi!
I'm Quyen Hong!
I'm come form Vietnam!
I'm developing a website Shop with Joomla 2.5.6 and VM 2.0.8e!
Everything same okey!
But when i change Currency of shop to: Vietnames Dong with:
Exchange Rate   : 0.0000 (default) <--- i can't change value of this field
Decimals: 3 (number 3)
Thousands Separator: , (comma)

Show when i check in my fontepage of site: Price: 14,000,00000 đ <------- My ploblem is here!
Why VM show 5 number 0 after comma???

How can i show price with 3 number 0 after comma?? like : 14,000,000 đ

This is my demo website:

Code Select Expand

http://beta.kienanh.vn

Plz, thank all ideal!

[attachment cleanup by admin]

[www.vn-boom.com]

Plz..help me!
I'm trying but fail anytime