If VoiceAttack is closed while "Thank you for trying VoiceAttack!" is the open window (E.G. as it has no window controls or taskbar entry, using Alt-F4 or the "End task" option in the "Processes" tab of task manager, which shut down VoiceAttack correctly otherwise), the "VoiceAttack Improper Shutdown" ("VoiceAttack Shutdown Issue") dialog will appear next time VoiceAttack is started.
While "LastStartup" and "LastExit" entries are generated in user.config when the window opens, and the former is set, the latter will not be modified on shutdown while on this window (if the config file was newly generated, "LastExit" will remain "00000000-0000-0000-0000-000000000000").
EDIT: Fixed in v1.7.8