I'm not sure why I slipped out of the habit- time and frustration, I suspect, and trouble with the tool I used. The PocketPC version of PhoenixStudio, my synthesizer software, was working fine, but my PDA's battery life and reliability was decaying; I got put off it by losing my work one too many times when the system mysterously failed without warning, dumping all of storage memory into the void of nothingness as is usual for a system that stores data in volatile RAM. (Stupid system. At least WM5 fixes that.) So I started using the PC version of the synthesizer- which was better in a lot of ways, but it never "worked" for me the same way- there was some serious impediment there that wasn't there on the PDA.
I've figured out what it was: the mouse versus the touch screen.
There's something about the directness of touching the musical pattern, even if I can't feel it as more than the friction of a vinyl screen cover under a plastic stylus, that helped the process for me, in a way that using a mouse didn't. The mouse itself was an irritant, an impediment to producing the music I wanted- but I didn't have a choice, with the PDA too unreliable and underpowered to produce the music effectively.
But now I have a reliable PDA, and PhoenixStudio has a 1.1 edition that works on Windows Mobile 5. I just bought it. It's not like I'm spending extra money buying the same program again; I never bought it in the first place, I just got a free copy for helping the developer debug the program and fix the imperfect translation of his manual. I decided to register it through PocketGear rather than asking Henrik (the program author) if he remembered me, because it's not like I've done much more for him since tweaking the manual five years ago, and he deserves the money, and I can- with a little budgeting- afford it handily now.
My suspicion about the mouse- noted from my own frustration while trying to use the PC version of the program- seems to have been correct. For the first time in a couple years, I have the start to a song that I'm actually happy with- I'm making a pattern I can play with and work from and build something out of, rather than a pile of dischordious crap that's never going to become a reasonable song, as has been haunting me the last N times I've tried.
Give me a month- I may finally have something new to show off.