Can’t use vim from Putty ssh session

I've successfully set up vim on my remote machine to work with telnet, in 256 colors.
However, I'm not able to make it work on ssh, even with the simplest configuration (no colors, just simple vim on ssh). I don't know if I've broken it with the color config, or it never worked.

That is, vim starts, but it freezes, it does not accept any commands: i, [Esc], :q, [Ctrl]-C… Nothing.

Here you have some additional info:

• vi works, but it is not an alias for a vim launch, it points to /bin/vi executable
• TERM is set to vt100
• I launch vim as: vim -u NONE -U NONE
• I've tried both -v (vi -compatible) and regular vim

My .profile:

set -o emacs

export TERM=vt100
#export TERM=xterm-256color

export HOME=/home/node.mgr

export JAVA_HOME=...

export PATH=$PATH:$JAVA_HOME/bin:.:$HOME/scripts

#
# bindings per i tasti direzione
# vedi http://unix.derkeiler.com/Newsgroups/comp.unix.questions/2005-01/0086.html
case $- in
*i*) #interactive ksh
  # This stuff lets the arrow keys work in an xterm...
  alias __A=`echo "\020"` # up arrow == ^p == back a command
  alias __B=`echo "\016"` # dn arrow == ^n == down a command
  alias __C=`echo "\006"` # rt arrow == ^f == forward a character
  alias __D=`echo "\002"` # lf arrow == ^b == back a character
esac

cd $HOME

Edit:
In reply to @RedGrittyBrick

stty output:

> stty -a
speed 38400 baud;
erase = ^H; kill = ^X; intr = ^C; quit = ^\; susp = ^Z; eof = ^Y
eol = ^M; stop = ^S; start = ^Q
-parenb -parodd cs7 -cstopb hupcl cread -clocal
ignbrk -brkint ignpar -parmrk -inpck istrip -inlcr -igncr icrnl
ixon -ixoff
isig icanon echo echoe echok echonl -noflsh
-tostop -iexten
opost -ocrnl

Besides,

• "Resetting Terminal" via PuTTY doesn't work
• I can't find "Are you there" command; I'm using PuTTY v0.61.
• vim –version | grep terminfo gives: … +terminfo…
• Sending SIG* via PuTTY menu has no effect
• changing TERM to xterm (both in env variable and in Putty session config) has no effect

Edit: In reply to @BlakBat

echo $DISPLAY gives empty string

> uname -a
NONSTOP_KERNEL svimi2 H06 20 NSE-A


> cat .vimrc
set nocompatible

set incsearch
set smartcase
set scrolloff=2
set wildmode=longest,list

set number
set nuw=6

set tabstop=4
set shiftwidth=4
set expandtab
set softtabstop=4
set autoindent

colorscheme elflord

syntax on

filetype plugin on

:let mapleader = ","

"fix backspace
:set t_kb
:fixdel