yahoo messenger not connecting,,is it any virus problem ?

since yesterday i m unable to sign in yahoo messenger,,,,,

i m getting following errors...........

*img3.freeimagehosting.net/uploads/ad4c3aa595.jpg

then after clking new user i m getting this error................


*server6.theimagehosting.com/image.php?img=y.5ef.jpg

pls check images......

i m using no proxies since 1 year and never faced any problem but facing suddenly.........

i have sify cable net....

remaining things are fine means opening of web pages..google talk is opening

and facing same problem for msn too .....even after troubleshooting i m unable to sign in msn too

and i m unable to open my yahoo mails too.......

pl help me urgently...........