You said you aren't working on HFS - does that mean this is the end to HFS once beta 24 is released???
no, not working at this time
i'm busy with my exams and job
but since HFS will be my thesis (for graduation) i will restart working on it for sure, if not now in next months
everytime when i reopen http://HFS Server page/ with Opera shows my username instead Login Button and the program HFS show status user@ip (without reEnter user and pass in LOGIN)
this is not a bug

as you can see, opera resend the user/pass, why should HFS reject it?
the fact is: opera remembers your user until you close it. to close the tab is not enough.
i'm an opera user and i already knew this.
there is no way for HFS to know you closed the tab in the while.