RE: Undo Problem in Loop IV?

["Clifford" <om@Om-Studios.com>]

This may have something to do with it- 

>From the EDP manual:

1-4 Echoplex Digital Pro User's Guide
If you don't like what you've just overdubbed, you can press Undo to
erase it. If your loop length is short compared to the amount of memory
in your Echoplex, Undo can erase the layers of overdubs one by one.
However, this capability is limited by the amount of memory that you
have installed. If your loop length is longer than half your memory
capacity, for instance, you won't be able to Undo at all.