Excel 2007 disables macro

I recently switched to Excel 2007. I have a macro that sends xml to my accounting software. Whenever I save the file and reopen it, the macro is disabled and Excel won't let me out of design mode. I've made a trusted zone with all sub folders which covers where the file is found. I've purchased a digital ID and signed the macro. I've changed my macro security to enable all macros and well as trust digitally signed macros. All have failed. Excel tells me to save the workbook and enable macros when reopening. Excel doesn't ask to enable even when macro security is set to Disable all macros with notification. Any help would be appreciated.