Impossible to use a macro defined in a 1.0 syntax document from a 2.0 syntax document

When defining a macro in a 1.0 syntax document:

http://incubator.myxwiki.org/xwiki/bin/view/Test/TestMacroSyntax10
or
http://incubator.myxwiki.org/xwiki/bin/view/Test/TestMacroSyntax10b

we can use it in 1.0 but not in 2.0 whatever the method

http://incubator.myxwiki.org/xwiki/bin/view/Test/TestMacroSyntax10UsedFrom10
-> using a syntax 2.0 include will include the white spaces and might break the macros by trying to convert them to syntax 2.0
http://incubator.myxwiki.org/xwiki/bin/view/Test/TestMacroSyntax10UsedFrom10b
-> using includeMacros or similar will not make the macro available

Be carefull since some cases can make the macro seem to become available. Always restart your engine if you think you have found a way. The macro could be in some velocity cache.