arduino creates strange files in SD card I'm new to Arduino and electronics. I want to make a project including SD data-logger, but I had a problem. I would appreciate if someone show me where I made a mistake.

Firstly, circuit  was set up as in picture:



I am using 8 Gb micro SDHC card with SD adapter. I formatted in FAT32. I can play audio files which are in appropriate format and read and the print contents of text files. 

But when I want to create a new file, strange file is obtained in SD card as in pic:



So I reformat SD card. the code that is used while creating file is as this;

// open a new file and immediately close it:
Serial.println("Creating example.txt...");
myFile = SD.open("example.txt", FILE_WRITE);
myFile.close();


Somewhere I read SDHC card with more than 2 Gb capacity  is not supported in Arduino and I bought 2 Gb SD micro with SD adaptor. 

But in this case aurduino does not detect SD card. please someone help me.
I've had similar issues with large (> 1Gb) SD cards, I've had various different problems with different cards, some things that helped me debugging the problem:


make sure your wires are the same length and try to use short wires
make sure your power supply is sufficient, sd card readers can draw up to 150mA
format the card in either FAT16 or FAT32 and never use "quick erase", try to use official tools (like https://www.sdcard.org/downloads/formatter_4/index.html)
make sure if you're the correct BAUD rate (9600) to talk to your card
filename support is pretty old so keep them short and don't use spaces or special characters
make sure the SD card is not in "write lock" mode, there's a small switch on the side of some SD cards that can prohibit writing (but will allow reading)