You probably need to set environment variable AFNI_MAX_OPTMENU -- this determines the max number of entries on the type of menus used for sub-brick choosers. The default max is 255, which is because some computer systems go bananas for larger menus.

You can set this variable in your ~/.afnirc file -- if you don't have one, you should create one. See the ubiquitously useful file [afni.nimh.nih.gov] for details about how this works and the many features of AFNI controllable in this way.

An AFNI feature that most people don't know about is that you can also right-click in the label next to such a menu (e.g., in the "Func" label) and you'll get an equivalent scrollable chooser pop up. This is for the case when the standard menu just becomes too big to deal with, which is where you are or are about to be.

bob cox