1d,1e,1f poison for data?

Hello

I have inserted texts with hex codes 1d, 1e and 1f into 6.5.1 and it seems
to that this characters totaly confuses the server, the vacuum writes that
the parent for record does not exist or that the record is to long.

Is that possible?
I am not sure that this is the reason but when I copy the table to file,
destroy it, created again a copy back through filter which removes those
characters, then the server workes well.

Should'n the data be parsed for such a character before they are inserted?

Thanks in advance
Richard Bouska