I can reproduce the time server problem, you can however stop the reboots by disconnecting the wan cable, which will let you log back into the router and "fix" your mistake.
I *suspect* that the reboots are related to measurement of uplink speed (somehow), which cased me all kinds of hassle when I updated to the new 1.22 beta (reset to defaults before and after the upgrade).
And curiously, despite the fact that I have the checkbox NOT TO MEASURE uplink speed, it SEEMS to still do it upon every restart. Or at least I get a screen saying that uplink speed measurement is being measured and the page will refresh shortly--bloody irritating every ~20 seconds when I'm reconfiguring the router, a task I've gotten very very well practiced at

.
As of so far, my impression of 1.22 is that its the same as the last 1.21 beta I was using, except 1.22 was a bigger pain about setup. And is still eating multicast mDNS traffic (in some fashion) preventing anything that uses mdns from finding each other.
Also, I don't know if its just me, but if I disable DNS relay (makes MDNS a little more reliable for some reason), and I've got the WAN port configured for a static address, and in the static WAN address I only give it one DNS server, the DIR-655 ends up handing off two static DNS server addresses to all its clients, the primary one I set for the WAN port, and 0.0.0.0. This has no affect on linux boxes (that I can find), but seems to confuse Apple Leopard machines, which try to use it as a valid DNS server... which it very much isn't.
I've got hardware version A4 by the way.
I'm also somewhat fuzzy on what uplink speed measurement is actually measuring, and/or if that's even useful to me. Especially since my DIR-655 is connected to another router as part of a larger local network segment (then the router I connect to is actually connected to the internet). This basically results in my WAN port being a LAN port.