AFTER slowing down in the first half of the year, the rate of homes entering foreclosure is rising again. First-time default notices were served on 78,000 homes in August, a 33 percent increase from July. A $1 billion federal program to help jobless and underemployed homeowners ended Friday. Foreclosure notices were filed against a record 2.9 million properties last year, and an additional 1.2 million in the first half of this year.