I am finding some multibyte columns (Unicode, Big5) are being truncated a bit, clipping off the last character. Why?
This was a bug present until a little after Slony-I version 1.1.0; the way in which columns were being captured by the logtrigger() function could clip off the last byte of a column represented in a multibyte format. Check to see that your version of src/backend/slony1_funcs.c is 1.34 or better; the patch was introduced in CVS version 1.34 of that file.