Tabs & formatting not working in Keynote '09

Weird problem -- tabs and other horizontal formatting aren't working at all within text blocks. I can set tab stops, but pressing the Tab key causes the whole line to shift, not the part after the insertion point. I can't backspace out of tabs, either. This is a problem, obviously. I've fully reinstalled everything. No luck. Any thoughts? I've checked all the text block formatting settings (center alignment, inset, etc.) They're fine.

Help would be appreciated!

Ron