We made P{βTub85D-GAL4.PK} several years ago. We used the βTub85D promoter and fused it to Gal4. We used it briefly and sent it out to a few labs (Maurizio Gatti, Barb Wakimoto). For all of us it simply stopped working. I still have a couple of lines that are as far as I know completely dead. Maurizio confirmed that his copies don't work either. Thus we never published anything on it.