I got an Arduino Uno on ebay. Its has an ATMEGA328P-PU chip in it (that's what's printed on it anyway).
When I compile my program with a small array everything runs smoothly and the hex file is ~8K big. When I add more data do my array, things are getting strange. Up to the point where the compiled hex file is ~16-17K big, the program runs smoothly. When I add more data making the compiled file even bigger ~22K, the program doesn't really run... With the smaller compiled file, the serial monitor prints all my debug Serial.print() calls. With the bigger files, it prints nothing or prints partial info (depending on the size of the compiled file).
Is it possible that the processor is from the 168 family with only 16K of memory? If not, what else can it be (I doubled and triple checked my code, making it super simple - just init an array with values and printing those values to the serial monitor).