I don't know how I missed this one.
I had the Putco bulbs for two days. Just by coincidence, I had the fogs and parking lights on at dusk one night when I went to pick up a pizza. When I saw the reflection of my fogs in the window, I shut them off immediately. The driver-side fog lamp was dim and orange. If I hadn't shut it off, it might have shattered and/or melted the housing. It appears that the one bulb (top) let in air at the base.
This is the first time I've ever had trouble with aftermarket halogen bulbs, since I always clean them with pure isopropyl alcohol (no residue) before installing them, and I never let the bulbs touch anything on the way in, not even the edge of the housing. I even installed them by removing the fog lamp housings, which are secured by three pinch-pins on the back of the housings, accessible under the front bumper. The other bulb was fine, but I took out both of them and reinstalled the factory bulbs.
Electrically, they work fine. They won't melt the housings or wiring, since that wiring should work with bulbs up to about 45W. But physically, while the electrical connector is the same, the pins are spaced slightly differently, and they're shaped differently as well.
Too bad, because they matched the color of my Silverstars.