Plusnet router appears to cause computer to freeze.

[#1]

Hi, I have just changed to Plusnet and my broadband was switched on this afternoon.  I set up the new router as instructed and plugged it into the ethernet port and left it for 15 minutes.  When I returned, the computer had shut down.  I restarted it and none of the applications would open.  I restarted it again without the router connected by ethernet and everything was fine.  I switched on the wi-fi and I could open one page on the browser before the browser then froze. Mail would not open. The computer then froze again.  I have an iMAC running os 10.6.8 .  I tried the wi-fi with a Mac book with the same os. The same thing happened. I then restarted the big computer without the router turned on, and apart from the internet, everything functioned normally.  I replaced the new router with one of my previous ones and put in the Plusnet account details.  The internet is now working fine - for ASDL. After waiting 1 hour 31 minutes on the phone and not getting through before the technical centre shut for the night, I am a bit frustrated, as the instruction on the website was to call that number if there was a problem with the router as the online chat was down.  Does anyone know of any conflict between the software on the current router and MAC OS 10.6.8?
Cheers.

[#2]

You need to disable ipv6 on your macs

[#3]

Thank you very much for that, dvorak.  It all seems to be running smoothly now. I was very impressed by the speed of your reply.  Cheers.

[#4]

no, worries. glad it's sorted for you.

[#5]

Sorry, but it is me again.  I spoke too soon.  The main computer connected by ethernet is now working fine, but the other MAC connected by WiFi isn't.  I went into preferences and switched off ipv6 under Network/Ethernet and clicked on apply on the other MAC, but when it connects to the WiFi it just freezes as before.  If I switch off the WiFi on the router the computer works fine (apart from no internet connection) but as soon as I put on the wireless connection it all freezes.  Is there any other settings I have to change? Cheers, 

[#6]

Does the MAC WiFi interface have a separate setting for IPv6?
I know nothing useful about MACs, however in a Windows environment, you would enable / disable IPv6 on each individual NIC.

[#7]

have a look at this thread here https://community.plus.net/forum/index.php?topic=137695.0

[#8]

In reply to Townman's question the setting on a Mac is specific to the network connection, so disabling ipv6 on Ethernet does not change the setting for wireless. 

[#9]

Thanks to both of you.  I had switched off IPv6 under the Ethernet Advanced settings but missed the one under the WiFi setting.  Now I have switched that off, all computers are up and running.  Just scanned what IPv6 is on Wikipedia and read the thread so have a vague understanding of the problem.  Thanks again,