Has anyone owned an Adcom GDD-1 Adapter?

I recently purchased one of these units at a clearance price. Does anyone out there have any experience with them? Opinions please.
I briefly owned one and had numerous operational problems, like locking up and/or garbled sound on startup and weird distortions at random moments. I have no idea whether these were problems with only my sample or with the design, but I returned it and moved on. Eventually I bought a used Lexicon DC-1 for about $1800 and have been extremely pleased. Are you experiencing specific problems with a GDD?
I don't yet have a complete HT system but I have tried it in two channel. So far it consistently hangs up and especially will not shut down. I bought it off of a clearance rack from AAFES (Air Force BX). I think I'll try to get my money back on this one and buy that other Curcio board I need.
I just bought a used Adcom GDD-1. It also has the garbled sound when the digital stream begins. I can get it to work correctly by pressing the Dolby Digital button. Does anyone know what the design problem is with this unit? Has anyone had one repaired? Also, there is alot of thumping noise when a digital stream begins or ends. Is this normal with other decoders or just an Adcom problem?