Macro conversion from Confluence 3.x to 4.x fails on mixed case macros

When upgrading a 3.x instance to 4.x, the macro conversion runs but ignores a macro that is defined with a mixed case. An example of this is with the Gliffy plugin macro:

However, on a page, the user defined the macro as

Even though this macro works fine in Confluence 3.x, it does not get converted to a 4.x macro.