$base_url not declared as global before modification.

Looks like a line of code got missed when refactoring...

securepages_redirect() uses it but does not declare it as global, while securepages_boot() declare $base_url as global but does not use it and calls securepages_redirect().

This is likely the cause of many issues I have seen listed( imagecache urls, form #actions etc...) , adding global definition to that function fixed these issues for me.

Will submit patch shortly.