Welcome to the forums Zerokool.
It might be a problem with how Acronis set up the partitions. I have to agree with Windygao on this one. If you want to dual-boot Vista and Windows 7, I recommend starting the installation from inside Windows Vista. During the install it will give you the options to install into a different part of the disk, and it will configure it's own bootmanager to include Vista as a bootup option.
It's best to avoid 3rd party partition programs as Vista and Windows 7 are intelligent enough to not overwrite other detected Windows installs if you don't install ontop of them. I can't begin to count how many people end up with odd or unusual issues with one of the two OS's after using a 3rd party partition manager.