Your sequence settings seem to have turned sour.
1. Open your User Preferences (alt-Q). In the editing tab, set Auto-Conform Sequences to Ask
2. Create a new sequence. The sequence preset doesn’t matter.
3. Drag your footage from the browser into the sequence. Now you will see a FCP message asking you it will cahnge sequence settings to match your clip. Select yes.
And then things should be OK.
Jaap