After a while, players can't connect to server

[Chazz]

So I revently was given a new router by my ISP because of a package upgrade, all well and good, everything connects fine... However, I now have a weird issue with MapTools. I can only think it's because of the router because that's the ONLY thing that's changed.

After the server's been running for about 10-15 minutes, anyone that attempts to connect gets an error of "unable to load". I unfortunately forgot to write down the exact message, if it keeps happening I'll update. People ON the server are able to stay connected, but if someone's connection drops we need to disconnect and restart the server. This does not seem to happen when other people host and we join them, but I/my room mate are the hosts simply because we have the fastest, most stable connection of our online buddies.

Has anyone else ever encountered a problem like this? If it's relevant, we're still using version 1.3.b89

EDIT: Was able to get someone to take a screen-shot of the error:

Again, this is only after about 10-15 minutes. It seems to happen more quickly if a campaign is loaded.

[aliasmask]

The router "may" have a setting for lease time. I remember I had an old router where it was set to 1 hour and it would boot me off my MMO every hour. Very frustrating. I never did figure it out until years later. I ended up just not using my new modem/router and put my old one back in. Only until I ran across an article did it dawn on me that was the issue.

[Chazz]

The default lease time is set to 1440 minutes, which is 24 hours, but considering it was happening in under 15 minutes, that doesn't seem to be the case :/