I'm sorry about the issue. Does your laptop have windows xp, vista, or 7, or 8?
How did you set up the Fn key with the spacebar? What's the name of the program did you open / use? Can you re-open it and check?
Can you click on Start -> All Programs -> TOSHIBA -> Tools & Utilities -> HWSETUP, then click on the Keyboard tab and check there?
If needed, disable the Fn function. Please see full information at the Toshiba website below:
If needed, click Start->All programs->Accessories->System Tools->System Restore and restore the computer to any date before this issue has occurred, and check.
Please reply at the box below to continue troubleshooting. Thank you.