Here's what I could find - although nothing I've found actually says that it does or doesn't effect the other languages? I think its mostly for Japanese characters from what I can see from here.... http://ja.wikipedia.org/wiki/POBox#POBox_Touch
I only use English Keyboard so I've just used Titanium Backup to delete it and I'll see how it goes and update if there are any negative consequences.
POBox (Predictive Operation Based On eXample)
POBox is a text input method based on context prediction and approximate pattern matching. It allows users to enter text much more efficiently on mobile devices such as SmartPhones and PDAs, with less typing. Invented by Dr. Toshiyuki Masui in 1998, it has been pre-installed in a variety of Sony products inclusive of cellular phones, VAIO PCs, and car navigation systems, since then.
With traditional input techniques in general, users had to enter characters one by one, and to provide all necessary information to the system before entering text.
For example, in case of handwriting recognition, users had to spell correctly and to provide the system with correct characters. Also, in a "Kana-Kanji conversion" system, users had to input correct pronunciation of the words.
However, most of the time, we do not need to provide the system with complete information about a word in order to select the word. For example, suppose you're trying to enter the word "input" in Japanese. The pronunciation of the word in Japanese is "nyuu-ryoku", and if you would make a list of candidates by filtering the dictionary and listing the most used words after entering just "nyuu", it is most probable that you will already see "nyuu-ryoku" on the list. In this case, 4 steps would be sufficient to select and enter the word, whereas 8 would be necessary in a traditional method.
Further to the above, once selected words will always be in the top of the candidates list from the next time with POBox, since it also comes with a learning capability. So, the more you use POBox, the easier text input would become.
POBox is also equipped with a context prediction dictionary. It checks the context and the characters specified by the user, and generates a list of candidate words for the next user input. For example, after "nyu-ryoku", we often find either "suru" or "****a" in Japanese, so there characters will be automatically included in the list of candidates for easy selection.
POBox was pre-installed in the au C406S mobile phone series back in 2000 in Japan, through a joint development betweene Sony CSL and Sony Mobile Communications AB. Since then, Sony Mobile has continued to further develop and extend POBox to POBox Pro, POBox Pro 2.0, POBox Pro 3.0, and POBox Touch, and is now pre-installed in all their mobile phones in Japan.
* "POBox" is a trademark or registered trademark of Sony Computer Science Laboratories, Inc.
* "POBox" is a technology co-developed by Sony Computer Science Laboratories, Inc. and Sony Mobile Comminications AB.