I am using an lm3914 in dot mode with 8 leds connected (which means outputs 9 and 10 are left open).
In dot mode I have an issue where the top led (led8) seems to be dimly lit. I had the same issue with led1 but I fixed this by using a 10k resistor connected across it.
If I switch to bar mode then the top led is no longer dimly lit.
In dot mode there is always some overlap so you never get a blank display in between zones. If this isn't what you are seeing they are a little prone to oscillations. Give the data sheet a good read in the applications area.