Ed,

I changed the filter about 7-10 days ago (I use EnergyAire MERV 7
filter from WalMart)

EnergyAire filters are designed to be energy-efficient, low-restriction
filters and don't do a very good job of removing mold spores from the
air. I would suggest using filters with a higher MERV rating. The
higher the rating, the better it filters the air.

I would suggest either the 3M Filtrete Ultra Allergen Reduction Filter
(MERV 11), a Lysol Elite Filter (MERV 12), or an Accumulair Diamond
filter (MERV 12).

Look at the Filters-now website for more information. Here's the link:

FILTERS-NOW.com, Inc

If that link doesn't work with your browser, type filters-now.com in a
search engine and you should be able to find it.

I hope this helps.
Ron