I have an Atmega88pa, it's signature is different than an Atmega88 but I have overcome that.
I need to have the ports PB7 and PB6 to act as I/O not as a clock. Several years ago I remember having a similar problem with a mega324. The fix, I believe, was to modify the L FUSE and H FUSE bits. I have tried to find how to do this using the datasheet to no success. Where can I find the info on what to program the fuse bits to or whatever it takes to use PB7 and PB6 for I/O?