I hope this may be useful to you.
1. The point that you give your module name as myCompanyName.myModuleName makes Visual Studio to treat anything after the dot as file extention. Then it mistakenly treat your module name as "myCompanyName".
My experience goes like this.
1. Name your module when Adding New item from Visual Studio (using the DNN template) as "myModuleName".
2. When you rename the folders in APP_Code and the one under DesktopModules, use this convention "myCompanyName.myModuleName".
3. Change, manually, all the namespace to "myCompanyName.Modules.myModuleName" or "myCompanyName.myModuleName". It is really a matter of preference.
4. Edit the myModuleName.dnn config file and the myModuleName.SqlDataProvider file. Change all referencea to myModuleName to myCompanyName.myModuleName, the later is your actual module name.
It should then work.
Happy DNN coding.