DSM-G600, DNS-3xx and NSA-220 Hack Forum

For the past week or so I've been attempting to resolve a problem with NUT Web Based reporting. Assistance from those in the NUT forum suggested two issue's might exist and that I should resolve the first one before moving onto the second. The first issue relates to the USB driver; usbhid-ups. When upsdrctrl is started the log file fills with the following;

Mar 18 19:50:48 DNS323_NAS daemon.debug usbhid-ups[8910]: Got disconnected by another driver: Device or resource busy
Mar 18 19:50:48 DNS323_NAS user.warn kernel: usb 1-1.2: usbfs: process 8910 (usbhid-ups) did not claim interface 0 before use
Mar 18 19:50:48 DNS323_NAS user.warn kernel: usb 1-1.2: usbfs: process 8910 (usbhid-ups) did not claim interface 0 before use
Mar 18 19:50:51 DNS323_NAS daemon.debug usbhid-ups[8619]: Got disconnected by another driver: Device or resource busy
Mar 18 19:50:51 DNS323_NAS user.warn kernel: usb 1-1.2: usbfs: process 8619 (usbhid-ups) did not claim interface 0 before use
Mar 18 19:50:51 DNS323_NAS user.warn kernel: usb 1-1.2: usbfs: process 8619 (usbhid-ups) did not claim interface 0 before use

According to folks in the NUT forum there is likely a conflict with another USB device or a hotplug issue. Unfortunately my knowledge is very limited in this area thus I find it necessary to turn to this group for suggestions on how to troubleshoot and resolve the problem.