I ran into this issue today and thought I would share the fix.

PROBLEM:

When connecting to a Mac, from another Mac using GoToMyPC I was experiencing very strange keyboard issues.  Symbols and alt charters appear, some keys we not work at all.

The screenshot on the right shows an example of the special characters that would appear while typing.

SOLUTION:

TextExpander was the culprit!  Quit/Close the TextExpander Application and you should be all set.

If that does not work, some forums have suggested closing TextExpander, then leave the GoToMyPC session and Start a new GoToMyPC session.

TextExpander is a wonderful program that saves me time everyday.  Here’s a description from the Text Expanded Website:

TextExpander saves your fingers and your keyboard, expanding custom keyboard shortcuts into frequently-used text and pictures…