Minor but weird issue with Viso

I have a design using this isolator for an ADC, where I pretty much just copied the reference design for the AD411X eval board. Both in that schematic and according to equation (1) regarding the voltage feedback in the datasheet, a resistor divider of 30.9kΩ/10kΩ will result in an output of 5V (Well, ~5.01V-- 5V is ~30.8kΩ/10kΩ). Now that I have a prototype in hand, I'm measuring ~5.15V on Viso. Like I said in the title, it's a very minor issue but I want to make sure that it's not indicative of something wrong (like some circuit structure is resonating, driving Vsel up). I haven't had time yet to look at it on an oscope, so so far all I've done is check it with a DMM. That's a next week task...