[Zope] charset in Zope-2.6.0 : Error Type: UnicodeError

[viriya]

Hi, 

I work with Thai charecter set tis-620 on 2.5.0 it run smooth but on 2.6.0
when I put Thai set in Properties Tab to discript a folder in Thai a 
messages shown : 

Error Type: UnicodeError
Error Value: Latin-1 encoding error: ordinal not in range(256) 

Can I set charector code  somewhere inside Zope-2.6.0? (I am a user who 
never known any program script but can followed by instuction sheet! :)) 

Thanks, 

Viriya