I just actually had two machines I just finished looking at that were also having dhcp issues just now. Both a Dell and a printer had failed to get dhcp addresses and had defaulted to their built in auto-ip addresses. (Both of these were machines that would have gotten 35.15 addresses because they weren't currently registered.) I just kinda wrote it off as a fluke, but maybe there's something more widespread going on? Yesterday I had a machine that I registered, got it's 35.10 ip address, then shortly after I got a call saying that it wasn't working again, and sure enough, it had a 35.15 address once more, but when I went into the registration stuff, it was recognized as having been registered (that machine I had to unregister and reregister to get working again).
Gary