That's normal. Reputation drops if you do nothing to gain more.
*Changes* were invisible, because for some bug reputation had jumped into the thousands, and there you don't see +5 or +10. :-)
I was selling stuff, at reasonable prices and my reputation continued to drop. Since it is just a number with no feedback or explanation, there is no way to know why it is changing. At the time it seemed like every ones reputation was dropping
