problem with certain websites

[#1]

Hi there
First of all, I want to say that I'm not an expert on broadband. I'd still appreciate it if someone could help me, so thanks in advance.
I've had plusnet for a few weeks now and it's all fine when I connect directly to the voyager 210 router that I got from plus net.
However, when I connect it to my wireless router (Netgear MR814 v2) there is a problem with certain websites. For example when writing an email on yahoo.com it doesn't work when pressing "send". The broweser (both Firefox and IE) tries to load the page but after some time it shows the browser error screen. The same happens when going on monster.co.uk  when entering log in details and clicking on "log in" button. I couldn't even log on this community!
Thus, it seems to happen when data is being sent to websites. As I said it doesn't happen when connecting direclty to the modem. Has anybody got an idea what router/modem settings I might have to change to avoid this?
Thanks!

[#2]

Hi Hendrixxx,
Hmm.  It sounds like a problem with something called "MTU".
Can you try downloading DRTCP from http://www.dslreports.com/drtcp
It would make sense to try using an MTU size of 1500 and to ensure that you have the same set on your router (there may be a setting on your routers configuration page).
Let us know if this helps!

[#3]

I think the problem is probably that the Netgear router has an MTU of 1500 (or something larger than 1400).
With the Voyager 210 the Internet side operates at MTU=1400 but the PC side operates at MTU=1500.  (Those are the default settings and I assume they weren't changed by the user.)  Because the router knows what it is doing it manages packet restructuring properly and access to all websites works fine.  The PC probably has the default MTU of 1500 and that works fine.
Some websites, often graphics rich ones (e.g. Microsoft and eBay), sometimes don't load properly with MTU=1500.  MTU=1400 almost always does work.  So to fix this problem when using the Netgear I think the MTU needs setting to 1400 on both router and PC.
I'm not familiar with how this is set on the Netgear so I'll pass on that.  As far as the PC is concerned DrTCP can be used to change it only if the Operating System is Windows XP (or earlier).  If it is Vista please post back for different instructions.

[#4]

Thanks spraxyt!
You're right the voyager is operating at 1400 and the netgear router was set at 1500. I changed the netgear settings and now everything's working fine!
Thanks so much, I wouldn't have had an idea how to make it work!