Hi,

I had a similiar problem with 'A' parts, as against the earlier non-'A's.

I changed the original pull-ups on the clock and data lines from 10K to 1K.

Solved the problem, and worked fine with earlier (non-A) Pics as well.

You migh want to try that; to begin with, dont bother pulling out the 10Ks, just solder 1K resistors in parallel to the 10K on the underside of the PCB. If it works, you could replace the 10Ks.

Hope this helps.

Regards,

Anand Dhuru