Table names showing up in lower case

I have some table names showing up in lower case
when I issue a select from dba_tables or dba_objects.
When I try and select data from them i get an error
saying they are unrecognized. Any ideas. How does
a table or object get created as case sensitive in the
database? I thought it forced all object names to
upper case.

If you have object names in lower case, use " around the name:

SELECT * FROM "your_table";

This is also the way to create (and drop) objects in lower case.
CREATE TABLE "tab"
( col NUMBER
);

DROP TABLE "tab";

As fas as i know tables migrated from Access can get created in lower case.