I too have a D7 and 3800 combo, I've only ever used the 32hz mode on the D7 one time whenthe show went longer and I knew i was going to run outta tape. The 3800 handled it perfectly. The tape was playing at 48, then midshow (between songs) it switched to 32. There are cleanliness issues , I believe, which cause the 3800 to spit out a tape it doesnt like. It's like self-preservation; give it poison, out it comes (like too much tequila!). I've rec'd several tapes like that via trades. Monitoring the error rate led me to believe the tapes weren't clean (from a dirty deck) and the 3800 spit em out at a consistently high error count.
I would tell the person to play back the tape in the D7 and tape it on the 3800. Then, chuck the 32 hz tape and never do it again.! It plays the tape slower and the D7 will die much faster using that garbage. Esp playing it back over and over. Tapes are $2,, decks cant be repalced too easily nowadays.
The 3800 is the workhorse that'lll plow through most anything. If that tape is coming out, I'd treat it like it's got mad cow.
If you bought that unit new in box, there shoulda been a wireless remote and a rackmnount kit that came with it.
Hope this helps
adamZ