wondering where my good sleeper went

I never thought I'd call Olivia a good sleeper, but she actually has been for the last few weeks (except the night when my sister and brother-in-law babysat - she was so keyed up that she wouldn't go to bed until I wrestled her into submission around 11:30 p.m.). Her normal schedule is to go to bed between 7 and 8 p.m., maybe do her weird waking up thing 30 minutes to an hour after going to sleep, sleeping through the night , and then not getting up until 9 a.m. unless I wake her earlier. Last night looked like this:

8:00 - bed
11:00 - wakes up babbling and laughing
11:15 - the crying begins
11:20 - drinks a bottle
11:30 - wide awake
midnight - wide awake
12:30 - wide awake
1:00 - wide awake

See where I'm going with this? At 1:15 she started looking somewhat sleepy, so I put her in her crib and crawled into bed, praying that she would stay asleep. Then she woke up at 6:58 a.m. Oooooooof.

And one of the cats hurled up their breakfast on O's play mat. Ugh. Nothing like cleaning up barf before breakfast.

In other Olivia news, lately when I ask her to say mommy, she grins and yells, "DA DA!" Stinker. The tooth to the left of her left front tooth finally broke through, and her fourth bottom tooth finally showed up (so much for that oh-so-helpful woman telling me it was never going to come in if it hadn't by now). Hopefully that's it for the teething for a while ... but what's causing the sleep disturbance?