The problem is your use of avwmerge.
Please read the following item from the FAQ:
This should sort out your problem.
All the best,
David Mack wrote:
>Sorry to keep on bothering with newbie questions but...
>I have combined 169 volumes using avwmerge. I am now trying to run a FEAT
>analysis of the data, however when I enter the filw as the input data it
>gives me a volume number of 338 (double the original) and when I try to set
>it back to 169 I get an error message during the analysis. Is there a
>reason for this or am I missing something?.
>Thanks Again for all your previous help...