Hey!
Trying out tixati on win7 64. When I load up a few downloads the cable modem starts cutting out and rebooting every 10 minutes or so. This doesn't happen with other clients that I can remember.

I have set download limits according to the guide, and tried both with and without the auto-limiter.

I does not seem to happen that much when there is only one download running.

Any settings I can tweak to remedy this?

This sounds like an issue with your modem.  Most likely, I would guess your modem's NAT memory is full and causes your modem to crash once the number of connection used by Tixati increases to a certain point.  You can limit the number of active torrents you have at one time, or you can try lowering the maximum number of peer connections per transfer and see if that helps.  It's also possible your modem is just overheating and restarting.  Try moving it to a more air circulated location if these other options don't work.

1.  Try setting your max active torrents lower.  Open settings, go to the "General" section under "Transfers".  Set Download slots and Upload slots to a lower value.
2.  Try setting your connections per transfer lower.  Open settings, go to the "Connections" section under "Network".  Set the number next to "Maximum peer connections per transfer" to something lower.  try setting it to half of what it is, or try something as low as 10 or 15 if that doesn't work.

If none of this works, you can also try disabling DHT and channels if you have those activated, since they both use a rather large number of connections at times.
(just go to either section in the settings and set the top-most dropdown to Off)

Ok, cheers.
I'm going to try your suggestions one by one. I suspect it may be DHT, now that you mention it.