Aaaaand... I think I finally realize what it is. At long last.

The CPU chips were not designed for something as monstrously complex as a sapient mind. There is a reason why even super-innefficient Nature allowed the human brain to enlarge to the size it did. A mind require physical support to exist. It cannot remain in a purely virtual form if there is no network to exist in.

This robot line was designed as child entertainers. It would be logical for their CPU chips to be simple. And as such... corruption is a problem. Then there is the lack of sleep ; without de-fragmentation, any mind will eventually break in errors. Organic or robotic, doesn't matter. De-fragmentation is vital. And this machine, simple and underdesigned, seems to have not been designed to handle a program complex enough to require de-fragmentation.