Hard to tell what is going on with the menu without seeing the code.
Before going any further thought you should make sure you are using the latest
version of Spry by going to the following page:
http://labs.adobe.com/technologies/spry/home.html - This is the official Spry
homepage. Here you will find the Spry updater package. Inside the package you
will find many samples and an Extension. Install the Extension and restart DW.
Then you will have a new menu option under the Sites menu to update your Spry.
Click on that and then re-upload the SpryAssets folder.