Firmata Servo Control

Good day

I am working on a robotic tank with CO2 airgun, but I am now stuck.
Please follow this link http://robotcontrol.yolasite.com/build.php to see what i would like my firmata control window to look like.
I am curently using the Old Standard Firmata Library, as the normal Standard Firmata Library is not working on my Arduino Deumlanueve, and i am controlling my 2 servo's on Digital pin 9 & 10 (pan/tilt).
This works, but the servos are jumping all over the place, and gears are creaking inside the servo housing.
I am currently using this FirmataVB - Downloads page ArduinoFirmataVBExtended.zip app, because you have the option to choose COM port & BAUD rate, so just by using the top section of this app & creating 4 buttons to pan & tilt a servo will be awesome

Please, can someone create or similar app for me to controll my to servos using any c#,VB.net or any other Windows XP compatable code and the scetch to control my Arduino via my PC's USB port.

Here http://blog.renatopeterman.com.br/?p=164 is an example of another app, but this only support the control of 1 servo on pin 9 or 8.

Please help me with this.

Thank you & regards

Riaan Deyzel