cant sign-in Jeban on Firefox !!!!

sorry for can't type Thai naka
i use my big sis's comp ...

have anybody got a problem like me ?

i use Mozilla Firefox
bcoz i cant update my Hi5 on IE.


well,
about ... a month
i cant sign in to Jeban on Firefox

after i click 'sign in'
it will bring back to homepage and still not sign in.

who knows why ?


bcoz from Firefox or juz smth wrong with my comp .. T^T



PS. pls help me naka ..  i have a lot of problem to ask u guys here
THANK YOU KA ​​    ...    : )