I have 3 exterior lights that are connected with 3 different types of X10 modules (all dimming though). In HG, I have the "turn on to 100%" module turned on and each of the lights is set to a dimmer. I can control the lights via an in-wall transmitter (XPT), the web interface, or the Android app correctly. I also have a second CM15A hooked up to a Windows machine running AHP with nothing configured (simply for logging activity).
Last night, when the lights were turned on via the XPT, the lights turned on to a very low level. The lights were at 100% on their last usage (we don't dim these lights). When I went back and reviewed the activity log, it did indicate that commands were sent to dim the lights to 22% for one and some other value for the others. This was also confirmed when looking at the AHP activity log. I don't have a repeatable test to see what's going on in that one case, so I'm not sure what to look at other than the couple activity logs and the "100% when turned on" code.