Actually using lower resistance resistors is better when taking the voltage drop on the regilators under load into consideration. For example, at 1V you may get a .99v with these resistors, but under load the voltage might drop all the way to .95v which is bad. For stability i recommend going with 70-75k for 1v, around 28k for 1.15 and 1.8k for 3.3v. 3.3v and 5v are less sensitive, so those should be fine with a higher tolerance.