matrix conversion warning

Need to investigate where this warning comes from:
```
> A2 <- getA(ped2)
'as(<dtTMatrix>, "dtCMatrix")' is deprecated.
Use 'as(., "CsparseMatrix")' instead.
See help("Deprecated") and help("Matrix-deprecated").
```
Spam?

And need to see if we can avoid it.

I started looking into this and am thinking that the suggested  `as(., "CsparseMatrix")` does not work for us here.