Tortoise SVN. Certain sub-directories won't update from main directory?

We're using SVN Tortoise at work, and when I do an update from the main directory, it seems to ignore files in particular sub-directories. However, if I do an update fro开发者_运维问答m said sub-directories, it will pull down the updated files. Any suggestions on why this is happening?

The subdirectories may not be where they actually belong. If on the server, you've got A/B and A/B/C, perhaps you're checked C out under A, and then C is being ignored when A is updated.