Loss of seal
My house in Township wasn't a Bobo, but my windows were made by Better Bilt, which was part of Peachtree Doors and Windows.
There is a rubber strip between the inner and outer panes of glass called a ''swiggle strip''. The area between the panes, and surrounded by the swiggle strip is injected with an inert gas such as Argon.
Over time the synthetic rubber in the swiggle strip deteriorates and the seal breaks, allowing the inert gas to escape and moisture laden air to infiltrate (hence the condensation or ''fogging'').
Peachtree warrants the seal in its windows for 10 years:
http://www.peachtreedoor.com/default.asp
This warranty does NOT include the labor to remove and install, however.
Even if you find the original manufacturer, and they are still in business, they are likely NOT to be making that particular style of window.
Your best bet is likely to obtain quotes from several replacement window manufacturers.
Let us know how you make out.