In the latest release of report builder it will no longer accept spaces betweenthe semi colon and the next email. It returns an error saying incorrect email. However when you launch the scheduler within report builder on the first screen you put all the email addresses in without a space. If you then click advanced options it will automatically insert a space between the emails. You then have to delete out all the emails and re-enter them without the spaces.
Likewise if you open scheduler in the web interface it will automatically add spaces even when you scheduled it without meaning you have to go back and manually remove all the spaces again before you can schedule.
This was not an issue on previous versions and it has stopped my colleagues from upgrading.