Strange thing in Bind8

[Nuno Teixeira]

Hello to all,

I found a strange thing in Bind 8. I have created a lot of subdomains for a
particular domain. Today I try to create a subdomain named
"softfiles.my-domain.com" and nothing, I can't ping the subdomain. But if I
change the name to soft-files, or other, then the subdomain is OK.

I think that it's very strange. May be related to cache or other thing else?

Please help me in this subject.

Thanks,

Nuno Teixeira