Does that have more to do with technical issues like error correction and the fact that immune-system-like programs are hard to design, rather than trust? What amazes me more than modern computers running multitudes of things with incredibly deep layers of abstraction, all with the CPU doing billions of computations without error, and all of this working at all, is that biological systems work at all. Biological systems are messy, but they work. Mostly. I don't trust my body to not just give up one day and quit for no apparent previous reason. (Lots of interesting cancer cases like that, one I remember: wake up one morning, start showering, suddenly start shaking all over, go to the doctor, body is infested with malignant tumors spreading through the blood system...)

If the error is more on trust, are you worried about a computer program misinforming your uploaded mind? Ever watched national news? Are you worried about one copy of you being killed by a cracker? Do you trust [some government] to keep your water supply clean?