From the 1973 Assembly on Home Rule in Illinois (my emphasis):
Municipal home rule referenda are dependent on implementing legislation as well as on constitutional authorization. Section 28-4 of the Election Code (“Referendums required by Constitution in respect to units of local government”)* sets forth the requirements for all referenda authorized by the local government article except for those provided for separately by the County Executive Act. Under this new section of the Election Code, a municipal home rule referendum may be initiated in one of two ways : (1) by resolution of the governing board of the local unit, or (2) by fiHng [sic] with the clerk of the local unit a petition signed by registered voters equal to 10 percent of the number who voted in the last general election in the unit.
Normally, you need signatures from 10% of the registered voters to place a public question on the ballot; but if you read through some of the material linked above, you’ll see that Illinois Home Rule plays by a different set of rules (and that it was designed to stay that way).
The City of DeKalb has roughly 23,000 registered voters. In the last couple municipal elections only about 6,000 of them actually have come out to vote.
So it looks like the Home Rule referendum group, aka Barb City Tea Company (aka Mac McIntyre, John Anderson et al) had with 782 petition signatures more than enough to get the question of retaining Home Rule certified for the 2009 Consolidated Election, and should not have been booted off the ballot.
Section 28-4 of the Election Code refers to a section of Chapter 46 of the Illinois Revised Statutes, which are not exactly the same as the Compiled Statutes (see disclaimer) and not readily available online as the Compiled are. However, placing the citation along with “Home Rule” in your search engine will yield the same citation in Illinois Municipal League and NIU publications.