If I uninstall Tasker, the Android Market ejects me to the home screen if I attempt to access 'My Apps'. If I reinstall Tasker (no tasks now), 'My Apps' works again. Uninstall, it breaks. If I reboot between uninstalling Tasker and attempting to use the Market, there is no difference. Tasker's enabled/disabled status makes no difference. If I force stop Tasker after installing it, 'My Apps' still works. If I force stop Tasker before uninstalling it, 'My Apps' does not work.
The tasks I previously used changed screen brightness by time, changed media volume by time, and responded to certain SMS messages with GPS data.
I don't *think* this is related to the 'Device Administrators' setting, since I have never enabled Tasker as an administrator and, when it is installed, it is not checked as an administrator.
I have not tried uninstalling Market updates at any point in my testing, since I have no control over when the Market updates itself again. If I should try that, please let me know.
This is by far the weirdest thing I've ever seen in Android. I wouldn't believe it if I hadn't tested it multiple times (with varied reboot cycles).
LG Optimus S, Sprint, stock (Sprint) Android 2.3.3 (OTA), Tasker 1.1.1u2.