Problem with all category with strange chars

It is impossible to add a site to a category that contains these chars: àèìòù.
Like:
'World/Italiano/Società/Relazioni_Personali/Contatti'
'World/Italiano/Società/Relazioni_Personali'

The web says that there is already the site in but if i click to "Edit" i get this error:

Bad category



No such category 'World/Italiano/Società /Relazioni_Personali'

Please fix this.
Thanks

It is very annoying, I agree - staff are aware of the problem though. However, there is a way around it: read this posting and follow the instructions under C. Hope that works

We'll have this fixed in due course. As nea said, this is a bug and staff are aware of it.