I have to upload huge files (400mb-800mb) to my website. Often after uploading 700mb of an 800mb file which takes about 3hrs. the server disconnects. Host provider claims it's not their problem.
Is there any way to continue the upload by appending to the already existing uploaded file?
Whenever I tried to re-upload, it deletes the 700mb file and starts over! Arghhhhhhhh

I'm sorry to say but I have had issues with larger files as well. I like DFTP but it has flaws, which is why CuteFTP Pro is my main FTP client. I'm not saying that DFTP is causing the issues by dropping out, but CFTP works well with the same servers and files so I can only draw the one conclusion.

I use CFTP for all heavy-duty work and DFTP for lighter, quick-edit type work, for which it is ideal.

Dave.

I too have problems with large files, for me it's in downloads though not uploads. My program prior to this was Bulletproof and it had trouble with large uploads and did exactly what you are saying it's doing to you in DFTP, and for me DFPT is doing exactly what it's doing for you only it's doing it on downloads not uploads lol. I dunno, guess maybe I'll update my WSFTP and see how that is going as I haven't used it in a few years, maybe they fixed their issues who knows lol.