Ricardo,
Try using lower value resistances for your resistor divider. 8K and 2K should work. The EN pin only sinks typically 300nA so you are not going to loose much efficiency. Based on a rough estimation for your power:
Power dissapation = (Vin - Vout) * Iload = (26V - 3.3V)*.025A = 0.567W
Junction temp = Operating temp + (Theta JA * Power dissapation)
Assuming that you are operating at 27C
Junction temp = 27 + (212 * .567) = 147C
The part is designed for a maximum 150C junction temp and the above calculation is only a rough estimate so you could be going over the junction temp.
Please take a look at TPS7A1633. This has a much lower theta ja as it comes in a bigger pakage with a powerpad.
Junction temp for TPS7A16 = 27 + (66 *.567) = ~65
Hope this helps.
Regards,
Kartik