"Probation" is a program's one chance - if they don't fix the problem(s) before the next site visit, the program is closed. Unless you're in the last year of your residency, you'll be looking for a job.
It depends on what the program has done to fix the problems; if there's been a good effort, you can be reasonably comfortable. If the hospital is on the skids, the PD has left and they haven't gotten another one, or some other deal-breaker, I'd be much more wary.