Playing around with my OFFSET(OFFSET mix, it seems that this is very very buggy. For instance, if you already have another OFFSET formula in the workbook, one or both may not return the correct result. And adding in some extra rows into the workbook sometimes fixes the issue, and sometimes not.
In short, steer clear of it.
By way of a demonstration, here's one weird thing that's been happening:
I put this in A1:F1 and named it d
1 2 3 A B C
In A2 I array entered =OFFSET(d,,{0,1,2,3,4,5},,)
When I evaluate this with F9, I get {1,2,3,"A","B","C"}, which is what I expect.
Then in A3 I array enter =OFFSET(OFFSET(d,,{0,1,2,3,4,5},,),,)
When I evaluate this with F9, I get {1,2,3,"A","B","C"}, which is what I expect.
THen in A4 I normally enter the same formula (i.e. I don't array enter it, but just push Enter).
When I evaluate this with F9, I get {1,#VALUE!,#VALUE!,#VALUE!,#VALUE!,#VALUE!}
When I go back and evaluate A2 or A3 I get what I did before, i.e. {1,2,3,"A","B","C"}
Now when I go and evaluate A4 again, I get {1,2,3,"A","B","C"}
This is weird. And this isn't the only weird behavior I've been getting when OFFSET(OFFSET is in the sheet somewhere.
