Calendar.core Not Found ?

[prof3ta]

If i go to calendar.php i can see the current month and eveyrthings normal, but if i click on a different month ora ny links to a diff date, i get this error:

Not Found
The requested URL /foros/calendar.core was not found on this server.

???
My problem is i havent used calendar in such a long time i have no clue if one of the hacks i installed is messing it up or whats the problem, I had even takne out the link off of the navbar, but now Im in GREAT NEED of th dumb calendar section....

Has anyone had this problem?

EDIT:------------------------------

so freaking weird... i just realized the problem is its trying to link to

foros/calendar.core?month=3&year=2005&c=1&do=displaymonth

when in reality it should be

foros/calendar.php?month=3&year=2005&c=1&do=displaymonth

I can change this in the code but still id like to know why this is like it is!