Re: [voice]
It's more that the system and their minds become incompatible. So, their likeness is taken out of the prison simulation, and they're left physically in stasis like the rest of us, just without the whole prison dream thing going on. That goes until the system finds a way to repair the compatibility. Once it's fixed, they come back, but not always with memories of being here, and sometimes from a different point in time from their original visit.
No one's been able to figure out how or why it happens, and why some people come back like nothing changed, and some come back not remembering or from different points in time.