newbie: why is my loop decaying?

[Tommy Kochel <touch.guitarist@verizon.net>]

I'm new to all of this, having received my EDP a few weeks ago.  When I
first used the unit, any loop I'd Recorded maintained it's volume
indefinitely (at least, that's my recollection).

Lately, after I Record a loop, the loop decreases slightly in volume after
each pass.  Yes, I've read the manual - many times and in different
directions.  But maybe I'm missing something.

Can one of you more experienced folks point me in the direction of a
solution?

Thanks,
Tommy