Hello

I have activecollab installed and running. My problem is that when I try to access through a computer with windows vista, I cannot log in.
The log in screen shows up (http://10.0.0.251/ac/index.php?c=access&a=login)

but when I type the user and password, the log in screen shows up again (http://10.0.0.251/ac/index.php?c=access&a=login&ref_c=dashboard&ref_a=index).

When logging from windows xp machines I have no problem.

Any suggestions on solving this strange problem ? Thanks