Yes that's right. The printer's Built in Webpage. Do that from a PC.
Does the printer have a print Job stuck? IF you disconnect the ethernet cable, does the rebooting stop? If not, try to cancel the Job by pressing the Red cancel button on the Front Panel.
I don't have a 7300 but I tested the 7300DT PPD (dated 6/25/09)on our 7500 from Lion and it printed ok so I don't think it is a PPD issue. I suspect that the problem is Communication related and Disabling the Unused protocols may help.
I have bad news for those with a 7300DT. Beginning with the Lion upgrade - everytime a print job was sent to the 7300DT, it would wig out. Specifically, the small scree on the face of the machine would rapidly blink and change color to red. When viewed on the network in a browser the status would be busy and wouldn't clear for up to fifteen minutes. I have been troubleshooting this issue for the last month with no real solution. Until yesterday - when I shared the 7300 on a MacBook Pro. Guess what? All the printer weirdness has gone away, so until a real solution comes along, I'll be using my MacBook Pro as a print spooler. Thought I'd pass this along until Xerox and Apple put their heads together and come up with the REAL solution. My network is all Mac, all running OS 10.7 except the MacBook Pro which is running Snow Leopard 10.6.
I'm in the same boat, but think I have found a solution. I have a Phaser 7300DN and upon installing the Lion upgrade have experienced the same problems with the printer rebooting endlesslessly. Since the 7300 print driver isn't supported for Lion, I've installed the driver for the 7400 which is provided on the xerox website. When installing the driver it says "model at location not supported" (referring to the 7300 at the IP address I supplied) but you're able to choose the driver for the 7400 and continue. I tested printing both a letter-sized page and a tabloid extra-sized page and both print. So far so good. The only oddity is that my printer status erroneously reports low toner (though window on the front of the printer does not.)