Used my Devilbiss SRI Pro Detail Gun for third time yesterday and it was sputtering/fluttering. Shooting unreduced Kirker epoxy at Devilbiss recommended 29 psi. I removed the epoxy, cleaned gun well, and shot acetone through it and it seemed to have the same problem. Any thoughts about what might be the problem? There isn't much to go wrong with this gun, so I'm not sure what might be causing this. The first two painting sessions went off without a hitch - the gun is really nice.