This is just bizarre to me, especially since I know so little.
Proftpd started working fine again, then stopped.
So I turned off proftpd and installed vsftpd and ran it. I could connect and upload files with vsftpd! yay!
So vsftpd let me connect and upload once. Then I tried to connect again, wouldn't do it.
Whatever is messing up would appear to be independent of the FTP server used, and seems to be a bigger problem. But I don't get it because I COULD connect at one point, and can (and transfer files) just .. rarely..
I have PC I'm using to try and connect to my (web)server that are both connected to the same router, which is connected to the internet/ cable modem.