Well there have been some recent developments that leave the immediate status of Warzone in a sort of limbo, I will try to explain whats been happening both in the past and more recently. Warzone is, as you know based on the Mutant Chronicles setting, which was developed by heartbreaker hobbies, which later became Target Games. Under Heartbreaker/Target Games three boardgames, a roleplaying game, and two editions of warzone were released. Unfortunately for gamers Target Games, for whatever reason, was unable to operate profitably and closed suddenly and without warning, leaving retailers with lots of unsupported inventory, gamers frustrated by a lack of support, and employees unpaid. During the Target Games closure Target Games was merged with Paradox Entertainment, another devision of the larger Target Inc., who focused on the development of electronic media such as video games, and also on brand management.
Paradox-Entertainment had no interest in producing non-electronic games and Warzone sat in limbo for some time until Thom and Excelsior Entertianment (EE) pursued the game. Paradox Entertainment granted rights to produce warzone, and Chronopia, under license to Excelsior Entertianment. Since then EE has produced the Ultimate Warzone ruleset (UWZ) and several new minis as well as putting the existing minis back into production and marketing them both online and through retailers willing to carry their product. The rulebook currently in the store is the current, and only edition of UWZ (perhaps you're remembering the cover from 1st or 2nd edition?).
Unfortunately, since Warzone was produced under license from Paradox Entertainment, the license must be periodically reviewed and renewed. In the most recent review Paradox Entertainment decided not to renew Excelsior Entertainment's license, stating that they had other plans for the brand. This means that Excelsior can no longer produce, develop, distribute or market products connected to the Mutant Chronicles Brand. This is the most current information we have regarding the game, if anything more becomes available it will definitely appear here on the forums.