[Brian]

I'm sorry for the confusion this is causing! You can correct this problem by doing the following:

Consolidate all the actions under one Miscellaneous list.
Change the name of the consolidated list to "New Miscellaneous".
Delete the empty miscellaneous list.
In the "Data" tab of preferences, check that the Default list for single actions preference is set to "New Miscellaneous" and not "Create when next needed".

If you're synchronizing with another Mac or an iPhone, please do the following steps.
(If you're not synching, you can skip to the "Finally" step, below.)
Sync with your server.

On each of the other macs, do the following:
Sync with the server.
Move any actions in a "Miscellaneous" project to the "new miscellaneous" project.
Delete any "Miscellaneous" projects in the database.
Set the default single action list preference to use "new miscellaneous" instead of "miscellaneous" or "create when needed". (It's in the "data" panel.)
Sync with the server.

Finally, once you have all the machines using the "new miscellaneous" project, you can remove the "new" prefix.

There are two causes of this problem. One would be the Data pane preference got set back to 'create when next needed' accidentally. Another possibility would be that two machines each decided to create a new miscellaneous project. Once they both synced with the server, you had two, and some of your machines were using one project as the default, while other machines were using the other.