Grumpy_Mike:
in the range of 200 KHz appear the work just fine; in the range of 60 MHz, the change attempts often cause I2C errors.
I would definitely say that was a decoupling issue with your layout. Read this:-
De-couplingThat is a high frequency you are dealing with and it can get into the supplies. I would also include a 1nF ceramic decoupling capacitor as well as the normal ones.
If you recall (reread some of your posts), we tried both large and small caps at the same time. There was no difference. However, I do believe you and I did read the article on decoupling (there are better descriptions). Unfortunately, I have had to put the project away for now. Perhaps in a few weeks we can try something more.
Sorry, but thanks for your help.