I'm using Windows 7 and my router is a wireless Apple Airport Express that is approximately two years old. Suddenly I can't access some sites (for example www.sthlm.friskissvettis.se, or www.vegetarian-shoes.co.uk, some streamed tv-shows on svtplay.se, and a number of other random sites) when connecting to internet with my router. It worked good until recently and I'm fairly sure this problem emerged when my ISP upgraded from 10/10mbit to 100/10mbit speed. Most other sites like facebook and google works fine.

When using my network cable to connect to internet everything works fine and I can access these sites.

Firmware is current and I've tried reseting the router to factory defaults.

Tried different browsers, and I can't ping the "blocked" sites either. Tracert www.sthlm.friskissvettis.se starts with 10.0.0.1 and continues through a number of long addresses until it says timeout. The last working address before timeout was sth-tcy-ipcore01-ge-0-2-0.neq.dgcsystems.net [83.241.252.13], if it matters. Tracert www.vegetarian-shoes.co.uk also eventually gives me a timeout.

When the network cable is plugged in, I still get timeout on tracert www.sthlm.friskissvettis.se even though I can access the site in Chrome. Weird. www.vegetarian-shoes.co.uk doesn't give me a tracert timeout when the cable is plugged in, and I can access the site as usual.

I've tried changing DNS servers to use opendns servers instead, but to no use.

I've tried pinging these two sites with a lower MTU packet size (with this method: http://www.richard-slater.co.uk/archives/2009/10/23/change-your-mtu-under-vista-or-windows-7/), but still can't access them through ping...

I don't know what to do anymore.... any suggestions???