Köszi, már megoldódott, egyébként ők is ezt javasolták:
@TCH: So, the solution is not to use FpHTTPClient.Get, but FpHTTPClient.HTTPMethod('GET' ... with allowed HTTP response codes 200 and 206 (success, partial success) and do FpHTTPClient.AddHeader('Range', 'bytes=' + IntToStr(cpos) + '-' + IntToStr(cpos + rlen)); before each request.
@miklos_akos: Nnna, Sophosnal csutortok este interjuzok. :D