Hi,
To me it happened the same... I could cause that it worked, making following: I included the subVI into the "Source File section" in the App Builder, adding a "Dynamic VI". Anyway, i recommend you, if you have still installed the old LV 7.0, you better uninstall it, because in other machine with only LV 7.1 in where there wasn't other version of LV, with "mass compile" it works fine.
I hope this helps,
JFT