"As to their allegations that we ignored complaints, those are patently false," Cohen said. "We certainly had no intention to mislead anyone. Kaplan's software just doesn't sell enough to be competitive with ours."

Cohen added that the lawsuit was filed at about the same time that Kaplan released its own GMAT book.

"[This suit] is nothing more than a public relations ploy to stem sales of Princeton Review Products," he said.

Kaplan, however, insists that its concerns are for misled consumers.

"What do you do with the 40,000 products that are out there right now?" Rosen said.

In fact, Princeton Review does not plan to recall the mislabeled products. Instead, it will offer a refund to those who want one or send them an updated version of the software.

But Kaplan is not the only party with a bone to pick with the Princeton Review.

The Graduate Management Admission Council (GMAC)-the group that writes the GMAT-also field suit against the Princeton Review with allegations of copyright infringement and false claims of an "authentic" computer-adaptive test.

GMAC and the Educational Testing Service are the only providers of authentic GMATs.

However, Cohen said that as of last night Princeton Review was awaiting signatures on a settlement with GMAC.

The settlement will involve changing the word "authentic" to "simulated" and modifying a graphic in the 1999 edition.

Hostility between Kaplan and Princeton Review is nothing new, according to others in the industry. The President of Peterson's-a company that makes admissions test guides-said he first heard about the lawsuit yesterday morning.

"We've been in the business long enough to know that [they] have been threatening each other for years, but nothing ever happened until now," said President and CEO Peter Hegener. "We all have a responsibility not to exaggerate our advertising. We are trying to convince the public that what we have is a good product and shouldn't misrepresent anything.