I just got some of my Lubuntu 12.04 systems upgraded to 12.10, and as part of that testing, tested Rosegarden. The version of Rosegarden that comes with Lubuntu 12.10 is Rosegarden 12.04.
The first test I ran was to play one of my demo-pieces, and it seemed the piece was poorly balanced (the relative volume of the different instruments was poorly adjusted).
On further investigation, I found that the settings of the knob-controls at the bottom of the Instrument Parameters pane, were different from what was loaded from the file (and worked properly in the earlier version).
Apparently, the "Pan" controls were all set to center (64?), and the "Volume" controls were all set to 100, which is different from what was saved in the ".rg" file (and worked properly in the prior release).
I do have the configuration parameter set to send the control values at the beginning of playback, but that was also the case with the earlier version, and the proper volume and pan values were used in playing the sequence.
I found that (using Rosegarden 12.04) if I changed the most-wrong volume knob to what it was supposed to be, Rosegarden did not notice that the sequence data had been changed. But if I saved it, and re-loaded it, it did get the proper initial volume setting.
It was disappointing that all of the "Pan" settings got reset to 64, since I had spent time getting the instrument-placement just right, and now all of that work gets discarded by the new version.
I have a recent development version of Rosegarden, and checked if that version has the same problem, and unfortunately, it does. It also loses the initial volume and pan settings from what is loaded from the ".rg" file.