I don't think it's ever not happened.
I'll start an application that depends on the drive being mapped, and it will fail. I'll open windows explorer and see the drive there with the typical red X. It then is clever enough to load the free space on the share - but it still won't actually work until I go into the share in explorer. Then it is mapped correctly.
Is there a way I can either automate that process every startup, or even better, actually have my drives map properly?