Does "encoding names" (see tclkit page about encodings) shows you the encoding that is needed for Cyrillic? Maybe you should repeat this command for tclsh8.5 and wish8.5 to see whether there are differences in the available encodings.
Does "encoding names" (see tclkit page about encodings) shows you the encoding that is needed for Cyrillic? Maybe you should repeat this command for tclsh8.5 and wish8.5 to see whether there are differences in the available encodings.