the answer to that is no, acc to this article
http://www.ahbbo.com/dbatmcom.html
it's a great discussion of dba vs trademark....but the bottom line (quoting from the article) is:
TRADEMARKS
As is evident from the purpose of registering a fictitious business
name, a business name is NOT a trademark and a registered
business name will generally NOT operate to protect the name
from use by others (except as an identical or deceptively similar
business name in the same county). So how do you protect your
business's "name" if it also identifies and distinguishes the source
of your goods or services from those of your competitors'? The
answer is federal trademark registration. (Although you can also
register trademarks at the state level, state registration confers only
limited benefits and should be considered only if federal registration
is not possible).
acc to this article dba is your 'fictious' name name of your company) and unless you are incorporated, you can't enter into a contract w/ your fictious name, but you must use your real name w/ dba....company x
the article is very interesting!