Spaces and certain other characters are inserted out of order after an input sequence is completed

1) Xubuntu 11.10
2) ibus-m17n 1.3.2-1ubuntu1

(Apologies if my terminology is not quite right here, by the way.)

When I finish off an input sequence by entering a character that does not continue the sequence further, it often happens that this last letter that I type (typically a space) will be inserted *before* the character that was being built by the input sequence.

For example, active grc-mizuochi and try to type a Greek alpha with an acute accent. Follow it with a space.

The input sequence would be "a/ ".
Expected output is "ά ".
But what I instead get is " ά".

Now, I found that if I edit the .mim file and add the following rule:
(" " ? )
Then the behavior changes to what I would expect. That is, I have to explicitly define the space character in the .mim file in order to get the result "ά ". In fact, I think that any character that is not explicitly defined in the .mim file will exhibit the behavior I describe above; the problem isn't specific to the space character.

This wasn't a problem with ibus on earlier versions of Ubuntu (I used it extensively on 10.10 and 11.04). Is there a way to get the old behavior back? Thanks!