I was wondering if anyone else had issued when plugging their Tetra in. I bought mine when it first came out and had to wait for the replacement AC adapter. I've hardly used it over the last year but notice when I do, i get a spark when I plug it in. It doesn't matter which end I plug in first, the tetra or the wall outlet, it always sparks. I was curious if this was an issue with the AC adapter. I was considering buying a new adapter from amazon but wanted to see if anyone else had the same problem. It doesn't appear to have damaged anything and what i've done to alleviate it now is to plug it in to the tetra then a power strip which is turned off. Once it's plugged in I turn the power strip on.