Hmmm, I don't see how that would solve the memory problem. I did change it to 13 and it performed exactly the same. I am running out of SRAM and the arduino is resetting itself. I had this problem before and when I put logread.close(); in both true and false of the boolean database function it worked but after putting in some more code it started to do it again. I checked over it again and it closes the file every time but the arduino is still resetting itself. Here is the Serial output when I hold a tag to the reader continuously if it is unknown:
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found
Initializing SD Card
SD Card Ready
Waiting for Tag
4E00047A81B1
No Match Found
4E00047A81B1
No Match Found