Needing help with menus

I have created a website on wordpress.com and have chosen a theme. I have created a custom menu and I am using the pixo point menu plugin. The menu runs fine for all the main pages on the website. However there are 2 problems:
1. When clicking on the title of a blog post on the home page of the website, you go back to the home page but with the menu changed to the default menu for the theme. The drop down menu are also disabled.

2. When using the search feature, the site returns the results of the search but with the menu changed to the default menu for the theme. The drop down menu are also disabled.

Can anyone offer any suggestions for fixing these problems?