whenever I open sajha.com or any threads of it, the site opens. Threads also open. In the status bar, it first shows 'done'. and then, one kona.kontera.com thingy appears which hangs my firefox. that thing causes my firefox to show that 'debug/report error/dont send' thingy and whatever I click on, it closes the firefox.

I appeal to any tech-savy people or 'better-than-me layman' to help me fix this issue. साझा बिना त बाँच्नै नसकिने भ'को छ।
my firefox is latest version. OS- XP. ad-ons in firefox are colorful tabs, forecastfox,session manager and AVG safe search.
antivirus in computer- AVG free edition.
Firewall- enabled.