As Robert alluded to, you might be building up too much heat, depending on what you input voltage is and how much current is passing through the regulator. If it is not way too much, adding a heatsink or reducing your input voltage might help.
The LD1117V33 requires the input to be at least 1.2V higher than the output to regulate properly at full output current, so, at least 4.5V. However, the higher you go above that, the more heat it will generate.
Also, I took a look at the schematic in the link you gave and it does not show an output capacitor for the regulator. The datasheet for that regulator states that it needs at least a 10uF capacitor connected between the output and ground to ensure stability. Something like the 478-5813-ND ought to suffice.