Program crashes after many serial outputs

Hi,
I have a problem with the Serial class, implemented in the arduino software. If I send many serial comands, the program works wrong or stops working. Do anybody had the same problem and solved it? How?
Could it be, that the problem causes in the buffer size of the internal serial buffer? If yes, how can I increase it?

Thanks in forward for your help
Michael

programcode:
(…)
Serial.println(“ENA <0,1> : 0:disable / 1:enable pushbutton control”);
Serial.println(“GEL : Get lower servo endposition”);
Serial.println(“GEU : Get upper servo endposition”);
Serial.println(“GIO : Set impulse time offset”);
Serial.println(“GIOF : Set impulse time for state ‘OFF’”);
Serial.println(“GION : Set impulse time for state ‘ON’”);
Serial.println(“GPC : Get center servo position”);
Serial.println(“GPL : Get servo position ‘Low’”);
Serial.println(“GPU : Get servo position ‘Up’”);
Serial.println(“HELP,Help,help,? : Open this help file”);
Serial.println(“INI : Set settings to default”);
Serial.println(“MOV : Move servo to position”);
Serial.println(“MOVI : Move servo incremental”);
Serial.println(“SED : Set servo endpositions to default”);
Serial.println(“SEL : Set lower servo endpositions to actual position”);
Serial.println(“SEU : Set upper servo endpositions to actual position”);
Serial.println(“SIO : Set impulse time offset”);
Serial.println(“SIOF : Set impulse time for state ‘OFF’”);
Serial.println(“SION : Set impulse time for state ‘ON’”);
Serial.println(“SPC : Set center servo position to actual position”);
Serial.println(“SPL : Set lower servo position to actual position”);
Serial.println(“SPU : Set upper servo position to actual position”);
Serial.println(“VERSION : Get the software version”);

(…)

I have a problem with the Serial class, implemented in the arduino software

No, you don’t. You have a problem with not understand how much (make that how little) memory the Arduino has, and with understanding that all string literals end up in that memory unless you take action to prevent it.

Serial.println(F(“ENA <0,1> : 0:disable / 1:enable pushbutton control”));

Really, wouldn’t a tip sheet and a MUCH shorter string be a better idea?