Have there been any theories regarding redistricting of Ohio...

since the 2000 election and how that could have affected the 2004 election?

http://www.fairvote.org/redistricting/reports/remanual/oh.htm

had this to say:

Who’s in Charge of Redistricting?

The legislature is in charge of congressional districting, while the Apportionment Board handles state legislative districting. The board consists of five members; the governor, the SECRETARY OF STATE, the state auditor, one appointee of the speaker and majority leader of the senate jointly, and one appointee chosen jointly by the minority leaders in each house. (Republicans hold three of these offices and will control the Apportionment Board in 2001.) The governor only has veto power over the congressional district plan.

Is there a source to get old and new district border?

that all the big, confusing changes are made in more urban/minority areas??