THE producers of “Chelsea on the Rocks” — Abel Ferrara‘s documentary about the Chelsea Hotel — are so upset longtime manager Stanley Bard was forced out, they boycotted the Chelsea last night and screened the film at the Jane Hotel. Bard, who loved artists, wasn’t as interested in profits as the new operators, who’ve been pushing some old tenants out. The movie features Ethan Hawke, Grace Jones, Bijou Phillips and Dennis Hopper, plus archival footage of Sid Vicious and Andy Warhol. A Chelsea spokesman said, “We would’ve liked to have had the screening here, but we weren’t asked.”