Is the boiler oil fired or gas ?
If oil, Could also be not getting enough oil when starting due to a plugged oil filter.
Have you changed it since the burner was installed ?
If a new one still gives the same problems, call a serviceman in.
(they should be changed every year anyway)
If it's gas fired, shut it off quick and call the serviceman
No one on usenet can offer you a guaranteed fix without seeing this.
AMUN