Contact "Show" Buttons Sometimes Missing

Using BCM 2007 w/ SP2 on Win 7 PC.

Just started noticing that when I open BCM contacts, sometimes the Details,
History or User Defined Fields buttons will be missing from the Show area of
the BCM Contact ribbon. If I open and close the record several times, they
sometimes come back - maybe one or two, maybe all of them. It is not specific
to any one contact record. I have not done any customization to this DB. I
have run the "check for errors" command on the DB from the BCM Manage
Database menu.

Open to suggestions.

Thanks,
Bill in Dallas
PS: sorry if this posted twice but I could not find the original post, so I
thought it might be lost in the nether world.