Kotoeri Produces Mojibake

Question

We recently purchased a 27” Intel Core 2 Duo iMac running Snow Leopard for my wife’s English-Japanese translation service. Unfortunately, after diligently indicating Japanese as one of the designated languages, we discovered that Kotoeri is virtually non-functional. When typing a word, for example, “日本語”、the hiragana "に” and "ほ” would appear, but then nothing would appear for "ん”。At first we did not realize this until after typing "ご”。Meanwhile, Kotoeri would retroactively erase "に” and "ほ”, and in place of the unrecognized "ん,” it would type "n.” Consequently, “日本語” comes out as “nご.”
Early this morning I tried every step that came to mind when trying to correct this issue. It emerged while using Microsoft Word 2008. I initially thought it was a Word discrepancy, until I discovered that the same thing happened in whatever program I used to enter Japanese. Neither selecting Japanese as the computer’s first language, tweaking Kotoeri’s preferences, nor deactivating all other languages other than English and Japanese solved the problem.
Thoughts? Your collective wisdom in solving this issue will be greatly appreciated.

Answer 1

Your suggestion to create another ID was the clue that provided all the answers. In the new identity everything worked fine which, as you duly noted, means either a software conflict or something screwy in the preferences. By process of elimination I zeroed in on the com.apple.Japaneseanalysis folder. When I dumped the two dictionary files and the environment file contained within and replaced them with the ones I copied from the new ID, everything was back to normal.
Thanks for your help!