[R] drop1: warning message

[Martin Bulla]

Dear R collegues,

I am new to R and do not understad the warning messages, which appear when I am trying to apply type III procedure to my glm:

> inkm$Gamie glm.inkmZ drop1(glm.inkmZ,test="Ch") 
Single term deletions

Model:
InkMb ~ IncStart + Vol + Gamie + PC1 + PC2 + PC3 + SpotsN + PC1:SpotsN
           Df Deviance    AIC     LRT   Pr(Chi)    
          9.3879 27.388                      
IncStart    1  14.6274 30.627  5.2395 0.0220791 *  
Vol         1  15.9723 31.972  6.5844 0.0102876 *  
Gamie       1  13.8659 29.866  4.4780 0.0343330 *  
PC2         1   9.6899 25.690  0.3020 0.5826585    
PC3         1  10.7326 26.733  1.3447 0.2462124    
PC1:SpotsN  1  21.6517 37.652 12.2638 0.0004618 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
Warning messages:
1: In glm.fit(x[, jj, drop = FALSE], y, wt, offset = object$offset,  :
  fitted probabilities numerically 0 or 1 occurred
2: In glm.fit(x[, jj, drop = FALSE], y, wt, offset = object$offset,  :
  fitted probabilities numerically 0 or 1 occurred

Where did PC1 disappiered?  What is the meaning of these warning messages?

Similarly, I do not understand where did PCs dissapeared in the following calculations:
> inkm$Gamie glm.inkm0 drop1(glm.inkm0,test="Ch") 
Single term deletions

Model:
InkMb ~ IncStart + Vol + Gamie + PC1 + PC2 + PC3 + SpotsN + Gamie:PC1 + 
    Gamie:PC2 + Gamie:PC3
          Df Deviance    AIC    LRT  Pr(Chi)   
         18.368 40.368                   
IncStart   1   26.078 46.078 7.7106 0.005490 **
Vol        1   26.515 46.515 8.1475 0.004312 **
SpotsN     1   18.663 38.664 0.2958 0.586537   
Gamie:PC1  1   20.418 40.418 2.0505 0.152155   
Gamie:PC2  1   18.460 38.460 0.0919 0.761818   
Gamie:PC3  1   19.832 39.832 1.4647 0.226180   
---

Any suggestions would help me greatly.
Best regards,
Martin