I had it with all browsers but the problem itself was with Mozilla 2.0 which was affecting all web based downloads.

If you have Mozilla 2.0 or earlier, update to the latest version and the problem will be fixed.

Ok I'm trying that right now, will report back in a minute.

Maybe your isp is throttling your connection. Where u a heavy downloader on torrents etc?

Nah, sometimes I download stuff. But certainly not all the time. Only have the program open when I use it. My point is that, downloading stuff with the torrent-program works fine. With browsers, not so much.

Also, a thing that might be useful to know. I have no problem downloading 5 mb files or even 10 mb.

But when it gets around 100mb it wont do.

I now upgraded to the latest version, but it didn't help.

Small add: When I let the download stay there for like ½ an hour without it going anywhere. It sometimes say: The download could not proceed, because the sourcefile could not be read.
Atleast that's what I've translated it to say
Mine is in Danish so..

It's probably a case of your download being cancelled for taking too long when that happens.

In English it usually says 'The connection with the server was reset.' or 'No response from the server'.

Did this problem start happening when you installed an application or did it just happen randomly? Have you tried downloading on another PC on the same network?

Also try downloading with this Free Download Manager and see if that works:

Free Download Manager - absolutely free download accelerator and manager

Do you have any proxies on or such and do you have an anti virus and what is it?