Brake Lights Come On With Head Lights

[A_Says_Full]

I have a 1999 A4 1.8T Quattro with 76k miles. I've had several repairs in the past year. It looks like I'm ready for another.
I just had a right rear brake light out so I decided to replace both brake lights. It was a week after changing the bulbs that I discovered my brake lights were not functioning properly.
If I have my headlights off, the brake lights appear to be fine.
If I turn on my headlights, my brake lights also come on as if I have my brake on(including the light in the rear window that I haven't touched). When I apply the brake, the lights do brighten slightly but not enough for another driver to notice. In effect, it looks like I'm riding the brakes and as you can guess, nobody can see when I'm breaking.
I've verified that all my other rear lights are functioning as expected. The only other recent finding was that my cruise control was being flaky sometimes working others not at all.
Is this some kind of weird indication that my brakes need maintenance? Could I have done something while changing the bulbs? Does anyone have an Audi over 75k miles that is happy with the amount of maintenance?
I've got an appointment at the Audi dealership in 2 days but my butt is still sore from the last bill only 1 month ago.

Thanks for the help!

[RickT]

you bulbs are repalced them with should of been single filement... if there were 2 fillement there will both shine looking like brake lights... ( i did it on mine before...
)

Cheers

[A_Says_Full]

Thank you. This wasn't the exact problem but lead me to the answer. My brake bulbs were double filament bulbs. All the other rear bulbs are single filament.
Auto Zone gave me the single filament bulbs. This is not the first time they gave me the wrong part, but it is the last time.