This problem is more of an annoyance than anything, but I figure I might as well try to fix it over the winter.
The bike is a 1993 VFR750 (hydraulic clutch--fluid has been flushed every 30000km or so). The original clutch plates and springs were replaced earlier this year @ ~160000km as the clutch had started slipping.
When the bike sits for awhile (ie. overnight), the clutch won't disengage properly. For example, if the bike is in gear, you can't pull the clutch lever in and roll it. If you start the bike from cold and drop it into gear, it's as if you've done it without pulling in the clutch (because it doesn't disengage). If you rock it back-and-forth a few times, it frees up and then functions perfectly all day. It seems to have to sit overnight for the problem to reappear.