About SAP Portal amount input field control.

Dear SAP,

I used this code:

nodeInfo.getAttribute(attribName).getModifiableSimpleType().setMinInclusive(BigDecimal.ZERO)

to control a amount input field.

When I type a minus into this input field ,it should warn me that the value should greater than or equal to zero.

In reality,when I use English to visit Portal, it's correct.But when I use Chinese to visit Portal,it always warn me like the image attachment.

Is this a bug or I used wrong code? If this is a bug,can you fix it and when? If I used wrong code,can you tell me the right way?

thank you!