I am using the LT3795 to drive 19 LEDs from 28V. Under certain conditions upon power cycle I observe the design not startup and start switching, and Vref is pulled down, Intvcc is good @7V however Vref is low. When measured with power removed it measures 97R to ground, I do have external circuits connected to this pin but only drawing around 50uA under worst case condition. The fault can remain for some time after power is removed, but in some cases the circuit will start working again on a power cycle. Also if I de-solder the affected pin (Vref) and measure with a DMM the fault is not present on my board or on the IC, I can then re-solder the IC and the circuit will work again. Are there any known issues with this device? Is there anything else I can check or could be doing wrong?