i don't think you ment to put 12 months.

I think most babies will do this until they get the hang of putting them selfs back to sleep. My DD just turned 6 months still will only sleep for short peroids sometimes.
Only in the last 2 months she has worked out to re-settle and will sleep for 2-3 hours ( this is only 1 sleep that i can get her to sleep for like this) it does get better.