Hi,
I would have to suggest that you start a Tech service ticket right away.. Then, I would ask if you had followed the uninstall process detailed in the Knowledge base?
http://support.presonus.com/hc/en-us
http://support.presonus.com/hc/en-us/categories/201264183-AudioBox-Family
Since you didn't specify what computer I cannot be more specific with this.
Other possibilities are your cables, and sometimes the shorter the better, especially with the Audio box. Often a powered hub can solve a NUMBER of issues, especially with laptops, and USB ports in general. (all USB ports are NOT created equal...) and my final thought, have you optimized your computer for audio? Laptops in particular have lots of performance killing features...