[R] newbie question on contrasts and aov

[Wolfgang Pauli]

I try to move from SPSS to R/S and am trying to reproduce the results of SPSS 
in R. I calculated a one-way anova with "spk" as experimental factor and erp 
as depended variable. 
The result of the Anova are the same concearning the mean square, F and p 
values. But I also wanted to caculate the contr.sdif(4) contrast on spk. The 
results are completely different now. I hope anybody can help me.

Thanks, Wolfgang

This is what I get in SPSS:
Tests of Within-Subjects Contrasts
Measure: MEASURE_1 
Source		SPKType III Sum of Squares	df	Mean Square	F	Sig.
SPK		Level 2 vs. Level 1	3,493	1	3,493	2,026	,178
			Level 3 vs. Previous	20,358	1	20,358	10,168	,007
			Level 4 vs. Previous	18,808	1	18,808	15,368	,002
Error(SPK)	Level 2 vs. Level 1	22,414	13	1,724			
			Level 3 vs. Previous	26,030	13	2,002			
			Level 4 vs. Previous	15,911	13	1,224			

This is the result in R:
Error: sub
          Df Sum Sq Mean Sq F value Pr(>F)
Residuals 13 205.79   15.83

Error: Within
          Df Sum Sq Mean Sq F value    Pr(>F)
spk        3 29.425   9.808  9.4467 8.055e-05 ***
spk: p   1  1.747   1.747  1.6821 0.2022649
spk: q   1 13.572  13.572 13.0719 0.0008479 ***
spk: r   1 14.106  14.106 13.5861 0.0006915 ***
Residuals 39 40.493   1.038
---
Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1



Spk.df <- data.frame(sub,spk,erp)
subset(Spk.df, subset=(sub!="14oddball" & sub!="18odd" & sub!="19odd" & 
sub!="20oddball")) -> Spk.selected.df
contrasts(Spk.selected.df$spk) <- contr.sdif(4)
aov(erp ~ spk + Error(sub), data=Spk.selected.df) -> Spk.aov
summary(Spk.aov,data=Spk.selected.df,split=list(spk=list(p=1,q=2,r=3)))

this is the the beginning of the dataframe, which I use:
         sub  spk    erp
1  10oddball spk1  2.587
2  11oddball spk1 -0.335
3  12oddball spk1  5.564
5  15oddball spk1  0.691
6  17oddball spk1 -1.846
10 21oddball spk1  1.825
11 22oddball spk1  0.370
12  2oddball spk1  3.234
13  3oddball spk1  1.462
14  5oddball spk1  2.535
15  6oddball spk1  9.373
16  7oddball spk1  2.132
17  8oddball spk1 -0.518
18  9oddball spk1  2.450
19 10oddball spk2  2.909
20 11oddball spk2  0.708
21 12oddball spk2  4.684
23 15oddball spk2  3.599
...