[ICOM] 706MKII off frequency

[Buck - N4PGW]

I started working on 6 meters yesterday.  I just put up an antenna and
started operating with some locals.  Last night the second contact I made
was .08 KC off frequency.  This morning I discovered someone else off the
same amount.  Today I am finding my rig is off by .08 on all USB
frequencies.  I don't know about LSB yet.  

Anyone have an suggestions about what is causing the problem or how to
correct it?

Thanks
Buck
N4PGW