Depending on TV model, there is an option in the TV menu either under "Picture" > "Theater Settings" called "Auto Aspect Ratio" or "Settings" > "Preferences" under "Display Settings".  Set it to OFF to prevent the automatic resizing. If you can not find the Auto Aspect feature in your TV menu or want more information about the feature, consult your TV's Users Manual available at support.toshiba.com..

Toshiba TV's give you the ability to manually change the picture size (aspect ratio) to many differnet formats (Full, Native, Theater, etc..). The Auto Aspect Ratio feature tries to evaluate what is being displayed and present that in the best aspect ratio. By default Auto Aspect Ratio is turned ON and when turned OFF it will retain its current setting until manually changed.