I have the first elements of a DVD movie (an .m2v and an .mpa file) that I actually write with my stand-alone DVD writer, and I can burn it direct to an empty disc with perfect quality. The only thing is missing now is a finishing touch, a Logo or something. After the help of some people (special thanks to Tommyknocker) I have found the solution to my problem, or, at least I thought I did!
The following lines are a step by step guide of what I have done until today. Please post a reply if you find something that I did wrong, or you have a better idea of adding a logo in a DVD´s screen.

1. I have install the the AVIFile frameclient to my VirtualDubMod
2. Altough I use XP, I restart my computer after the frameclient instalation.
3. I open my OLD.m2v file in VirtualDubMod.
4. I have my logo added and then I pressed the "Start frame Server" button.
6. I press the start button on the following window, and
7. I have gave a name for the .vdr file.
8. I pressed save (NEW.m2v), and then.....
9. I opened the TmpgEnc, and I loaded the DVD PAL template, so that in the left down corner of the program uppears the following combination:
DVD PAL (MPEG-2 720x576 25fps CQ 65, Layer-2 48000Hz 384kbps)
Since I used a .m2v file without audio for the moment, I have selected: ES (Video only).
10.The result was good but not perfect because the quality was reduced, but moves were smooth and no other problems were to noticed.

11.After, in my next 2-3 tests I have changed the CQ in many differend values, and finaly I was with the impression that CQ 80 was my best choise.

12. But the problems were continued to exist! Sometimes my files were become so big that won´t fit in a standard DVD-R, and some other times my files become very little and that results loss of quality.

13.After this I decided to read more and understand better how the hole system works, and why is my quality "flies away" the most times. I thought that my choise of letting CQ (constant quality) was a wrong one, and I decided to change it with a high CBR (constand Bitrate). I have made many tests, and finally I decided that since I want to fit a 90 min film in a DVD the best value for CBR is around 6000.

14.My next 3 films were fantastic! I was happy and amazed that after two weeks of trying and emailing and and and, I had the better results ever!

15. AND THEN IT HAPPENS!
I noticed that in some films I tried to burn, a serious problem in movement. It appears like it freezes and beguns, freezes and beguns,over and over. This is mostly appears in scenes with crowd movement or even a car movement, or what ever crosses the screen from the one side to another.

Another thing that I must maybe tell you is that in the computer the files are playing good but the problems begun after the burn sequence on the disc.