[R-sig-ME] Problem with overfitting

[Iker Vaquero Alba]

    Hello all:

   I am trying to fit a model with lmer and doing a split-plot simplification. The data are attached. The problem is that when doing some of the anovas to compare different models, I get a p-value of 1. I have been told this may be a problem of variable overfitting. But I am doing simpler and simpler models and I still have the same problem, so I don't know where is really the problem. This is the last one:

   broodmodel6<-lmer(brood2~briventral+inslarge+weatherpc1+sex+briventral:sex+briventral:inslarge+briventral:weatherpc1+(1|site/pair)+(1|year),family=binomial)

   When simplifying "briventral:sex" and comparing the two models with an anova, I get a p-value of 1.

   Any help, suggestions and ideas will be welcome. 
   Thank you very much.
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