Matter of Camarillo, 25 I. & N. Dec. 644 (BIA Dec. 2, 2011) (any period of continuous residence or continuous physical presence of an alien applying for cancellation of removal under section INA 240A is deemed to end upon the service of a notice to appear on the alien, even if the notice to appear does not include the date and time of the initial hearing).
http://www.justice.gov/eoir/vll/intdec/vol25/3734.pdf