Boy, this sounds familiar.
It seems serving bloggers subpoenas is a favorite activity of some Chicago lawyers. In my case, it took three trips to court and over three months of legal costs in attempt to quash the subpoena, only to have the subpoena rendered "moot" when the case was dismissed.
I encourage anyone else who might have this occur to contact the Electronic Frontier Foundation, a San Francisco-based organization that defends the First Amendment rights of those who use the Internet and other digital media to exercise their freedom of speech. It could save you a bundle.
In my case, by subpoena was "served" to my front desk clerk, came with a cover letter claiming it was a "Second Notice" (I never received a first notice), and was "served" just twenty-four hours before I was due to appear to make a statement in the attorney's office in person without any offer for reimbursement for time, parking or travel.
I'm telling you, it happens.