This is my sin.

Back in Febuary (around the 25th) I modified c1sus.mdl, removing the simulated plant connections we weren't using from c1lsp and c1sup. This was included in the model's svn log, but not elogged. 

The models don't start with the rtcds restart shortcut, because I removed them from the c1lsc line in FB:/diskless/root/etc/rtsystab (or c1lsc:/etc/rtsystab). There is a commented out line in there that can be uncommented to restore them to the list of models c1lsc is allowed to run. 

However, I wouldn't suspect that the models not running should affect the suspension drift, since the connections from them to c1sus have been removed. If we still have trends from early February, we could look and see if the drift was happening before I made this change.