I have seen the very same thing on two occassions - once with a telescope. It was a weather balloon. Both times it was in the same area of the sky you describe and the same time of day.
Scott Busby
A.K.A. Reconair

Carpe Noctum
Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth.
- Ptolemy,c.150 AD