URL Alias for categories are created with a space instead of the seperator character

After a bulk update with the following path pattern for categories

[vocab]/[catpath].html

and the seperator character set to _ (underscrore the default)

the category url aliases are created with spaces in this format;

/vocab name/catpath name/.html

Problem also remains if the sperator character is removed completley, the node url aliases are created correctly on a bulk update however the category url aliases are not.