First, on the Zell side: taxes. When the Tribune bought the Cubs 28 years ago, it paid around $20.5 million. To sell the team for nearly $1 billion today would then mean a massive capital gains tax. Zell is therefore trying to structure a deal by which he would maintain some slim ownership in the club, effectively holding back on his cash windfall so as to avoid the revenuers. The idea would be to ratchet down that ownership piece over time until none remained. At issue in striking a deal, therefore, is not only the percentage, but also the duration. On the Ricketts side, the alleged hold up has been: Media. The Tribune has long owned WGN, the superstation, which holds broadcasting rights for a bulk of the Cubs' games. (The Tribune had come to see the Cubs not as a team with title ambitions but, instead, a source for reliably high-rated WGN programming, which would bring the ad dollars.) At this point at least, the Tribune is not selling WGN, and a new broadcasting agreement -- at arms' length, as they say, between the channel and a separate Ricketts' owned club -- needs working out. The rights fees and to what degree those fees escalate over time is at present a big source of contention between Zell/Tribune and Ricketts. So tense did discussions become that the Zell people, several months ago, brought the "runner-up" bidding group back into the picture. The group is led by Marc Utay and Leo Hindrey, two old deal veterans.