anybody else have this problem?

if its a standard idler the centre tube is clamped to the mount by the bolt and all idler action is the flex in the bush
i.e the loosness of the bolt through the idler centre when in a 2 sided kframe or chassis mount should not be an issue...in a 1 sided mount i'd guess it might be no experiance with them.
if the idler swiveled around the bolt....then you'd have a problem, but it doesn't in standard operation.