It is a known bug that devices can't be renamed within SecurityCenter. Hopefully will be fixed with the 2011 release later this year.
Thank you for answering that portion, but is it also a known bug that it doesn't save ANY home network settings? Not only can't I rename my PCs, but apparently my home network completely disappears off of the "Home Network" map. Like I said before, my other 2 PCs have completely disappeared as has my printer and other items. So, is the home network feature totally useless now?
It shouldn't be doing that. I suggest opening a case with Technical Support Chat via Useful Links above.