Well, maybe not a capital offense. But it should be grounds for a good smack, at least.
If you've used a computer you've probably run into an installer that does the Refilling Progress Bar Trick before. Where there's a progress bar that slowly fills up to 100%, only to immediately drop back to 0% and restart the process.
Now, there's nothing wrong with having status bars displaying multiple steps. But please indicate it! Have a "master progress bar" that shows how long the entire process will take. You can have your individual task progress bar too, if the entire process will take long enough that there's no sign of progress without the task progress bar.
But a progress bar that continuously refills is just infuriating.