Intermittent line drops / router restart

[#1]

Hi,
I've been on the fibre trial for some time now, but recently have started to notice an increased frequency of connection problems, although my usage has increased recently as well so it may just be me noticing it more.
Every so often, and there doesn't appear to be any significant pattern, I lose connection to the internet from my main, wired PC and upon logging into the ZyXEL router see that the router has restarted itself. Sometimes it will pick up a new IP address from the modem and connect straight through, other times I need to manually restart the router. On no occasion have I had to restart the modem to regain connection.
Unfortunately as the automatic restarting of the router clears the logs out, I've not yet worked out a way to track this comprehensively - suggestions would be appreciated - and as I can't log into the modem can't get any information from that side either.
Any suggestions as to what may be causing this, how I can help diagnose the problem and what can be done to rectify?

Cheers,
Chris.

[#2]

From our point of view your connection seems to be quite stable, infact the current connection has been up for over 2 days now. The router restarting on its own and clearing the logs certainly isn't right. I'd try a factory reset then if it't still an issue you may want to consider trying another router.