I had a similar plant that I kept in a pot on the deck each summer. When brought indoors to lower light in fall, it would lose a good portion of it's leaves but then regrow new ones indoors. Similarily, in spring not matter how gradually I tried to acclimatize it to the outdoor light, it would lose leaves again and have to regrow them. It was nice and bloomed quite a bit though.

Thanks for the reply! I have it outside on our deck again, and it is growing healty leaves again. To be safe, I will always bring it inside for the winter. I would hate to loose this plant/bush.

Many plant grow leaves that can take the level of light there exposed to (with-in set peremiters). When you dramitically change the light exposure the plant will shed its leaves and grow new ones better suited for the enviroment.