I had been updating the above message, but those updates disappeared. The frustrating timeline of today so far:
1. My sequence wouldn't open -- no presets error
2. I notice that when I create NEW sequences, the DSLR presets are no longer offered.
3. I uninstall and reinstall, same issue. Does it suddenly think I'm not a paid customer and has therefore busted me back down to some trial version?
4. I call customer support. The technician in India suggests I uninstall the old demo version of CS5. Then he says "give me your number so I can call back if we are disconnected." I begin to give him my number. He hangs up before I finish. I guess the "give me your number" ruse was so I wouldn't guess he hung up on me?
5. I uninstall the CS5 trial version
6. Now CS5.5 won't open at all -- it says it can't authorize my copy because I'm not connected to the internet (I am, and it is not blocked.) Argh.
7. Uninstall, reinstall. Now it works.
> Now it works.
Does this mean that you don't need any further assistance?
In the future if you uninstall run Adobe's cleanup script at least once before you try a reinstall.