Windows 7: ISP issues

so our isp gives us dynamic ip addresses every time we connect

one range is : 203.177.0-255.0-255
another is: 180.190.0-255.0-255



my question is why is that i can't access some sites while using the 2nd range of IPs, like for example Xperia or www.thepiratebay.se ,,,,,,,,, it just keeps on loading. and when i check if it's available on Website down or not? - Website availability check, it is. This happened before for a while and disappeared and now it's back

but when i reconnect and have an ip of the first range i can access it.

can anybody explain why? here's two ip addresses in case you need to scan it or something 203.177.74.136; 180.190.160.183

Likely abusive users have used those ips in the past and the site admins have blocked it for that reason.
There are also regional blocks on some websites that will be triggered by certain ranges.
(this is horribly inaccurate and often leads to the wrong people being blocked.)