Rapidshare problem

First i go to the link posted in a thread, then as usual I 'tick' the box "free" down and on the right hand side of the page. Then the countdown begins. After the countdown has stopped, all the free users have to enter a code, which consist of 3 characters. Normally, when you enter the code correctly you get a "pop-up" so you can start downloading by ticking the box "save as".

I'm having problems with rapidshare for over 2months now, my problem is: after I enter the code, the download doesn't start and rapidshare opens up another page, on which they tell me that there has been an error (and they give possible reasons):
Download-session expired. Direct-links last a few minutes for free users and a few days for premium-users.
You requested this download-session from a different IP than yours. If you use AOL, try a different browser.

I have used the same computer for over 2 yrs and only had this error for about two months, I'm desperate, someone please help me!