Random device added to my network?

I have the XFi app and I have an 18 character password for my wifi network consisting of random numbers, letters and characters.

Last night, at around 12:30 am, I got a notification on my phone that said a new device was added to my network. The name of the device was epigram-502a.

I actually searched for this and there was a post back in 2004 about a guy who noticed his d-link router changed names and MAC address. I also did a lookup on the mac listed but it just shows up as epigram inc., which oddly was bought out in 2002 roughly by broadcom if I recall...so that makes no sense.

Has anyone ever seen this before? Can't you look up what TYPE of device it is by the last half of the MAC?

Any help would be appreciated. Thanks.