[R] errors using step function

[silvia narduzzi]

Dear R users,
I have had a problem using the "step" function for the selection of the variables from a gamma model with log link function.

CODE:
step.glm.gam1.infroma <- step(glm.gam1.infroma, direction = "backward", k=2)

ERROR MESSAGE:
Error in glm.fit(x[, jj, drop = FALSE], y, wt, offset = object$offset,  : 
  inner loop 1; cannot correct step size
In addition: Warning message:
step size truncated due to divergence 
 

Could someone help me???
Thanks


Silvia Narduzzi
Dipartimento di Epidemiologia
ASL RM E
Via di S. Costanza, 53
00198 Roma
Tel.: +39 06 83060461
Mail: narduzzi at asplazio.it