There's an old behavior that I'm pretty used to, but it still occasionally bites me (usually with references). It happened again today, and it got me to wondering if it's really intended behavior.
If you pass a value into a zero iteration for loop, then send it out the other side, the value exiting the for loop is returned to default, not the value you fed in (see simple.vi, LV7.1).
This is expected behavior...the workaround is to use shift registers to pass the value through instead of tunnels. I believe this is discussed in the LabVIEW Help.