Symbols in the Insert Math dialog don't look right.

Prism lets you insert Greek, Math, etc. characters right from the toolbar. Click the button labeled with an alpha, to bring up the menu or dialog. 

If you use a Japanese or Chinese (and presumably other languages) version of Windows and Prism 3 or 4, the math symbols will look wrong and many symbols will be missing (replaced by other characters). This is due to the fact that Prism doesn't use unicode. One solution is to switch to English language within Windows. If you do that, all should work fine. 

The problem has been fixed in Prism 5. So updating will solve the problem. If you want to keep using Prism 4 without switching to English, try this workaround:

1. Download and install the Prism 5 trial (demo) version.
2. Create an empty project in Prism 5.
3. Go to a layout, delete all placeholders, and create the text object with one symbol "±" on graph and save project. 
4. Open this project in P4. 
5. Copy the symbol you need, perhaps "±".
6. Switch to the project where this symbol is needed and paste.