The exact same thing happened with mine!Which way are you speaking about leaning? When I got my '83 last year, I was concerned as it sat upright too much and I was concerned about it tipping over to the right. I thought that the sidestand was messed upsomehow but I didn't see any apparent damage or modifications to it. As it turned out, it was the suspension sagging not the sidestand. When I aired the shocks up to max, the bike sat as it should. With the new progressives I installed this spring, this leaning is no longer an issue.
Just my .02's worth.