Windows has a “large font” mode under the advanced display settings which turns everything into 120dpi instead of 96dpi, it makes some fonts larger. I would guess that at least 25% of the people out there use it because at high resolution the fonts are too small on most monitors.
Something is wrong though with the number of queries used on your pages, I am worried a plugin is malfunctioning under 1.0 – can you tell me what plugins you are using? Queries are how bbPress gets data from the database. Each kind of info needs a query, a user, a forum, a topic, etc. A clean install of 1.0 with some forums/topics uses probably 15-20 queries for the front page, yours is using 35 which seems excessive.