Some parts of the screen show a double vision

This is most certainly a display problem, as in, a problem with the LCD panel. I used to fix 4 or 5 LCD's a day and had a few with the same problem. It can be fixed by being replaced.

replaced convergence IC.what is the model#?

you need new convergence chips, there are 2, part number stk 392-110, also you must check for burnt resistors, if you don't have very good soldering skills at least, you will need a tv repairman.

Not too familiar with this exact model but am very familiar with Samsung DLP. If this is a Rear Projection (3 CRT's R.G.B.) it is surely the convergence chips ($12 each X 3). If this is a DLP (Color Wheel @ 7000rpm) this is not good news as a DMD board for Samsung DLP is around $400 (not retail either, warranty part price).

yes the convergence problem leaves a shadow of red or blue like an outline around the picture, sometimes part of the screen some times the entire screen.

Chances are that the convergence amps are bad.
If those are mounted on a separate board, replacing the board would be the easiest thing to do. Running the magic focus or touching up the convergence in the customer menu may be required.

You need to replace the two convergence ICs they are STK392-110 you can get replacements at the following link with fre installation instructions.
http://servicemanuals.vstore.ca/

Panasonic Projection TX-51P100H has double vision, shadow is red

We recently had the same problem with our church projector and we too had just changed the lamp. I read somewhere while searching for an answer that if the cable input is loose it will cause double vision of the text. Sure enough, the cable was loose and after tightening the text cleared up immediatly.

Check the VGA plug and lead between the monitor and computer.

Does it get worse or better while you move the lead around?