I just logged in to the site and when I first clicked a link I got a message that I already have reached my limit for the day, why?
There are several different reasons that it would happen:
Your download counters weren't reset yet.
To find out when your counters get reset, go to the 'My Account' page.
You have a web-surfing accelerator active on your computer or your browser have that feature (usually called pre-fetching or offline browsing). In that case you must turn it off otherwise you'll always get that message.