Description of problem:
libpinyin should remember user preference after user choose correct candidate and commit. For some special terms or words in Chinese, like "hong mao" (pinyin for RedHat), after user chose the correct candidate and commit, then input again, libpinyin still display incorrect result and can not remember user preference.  

Version-Release number of selected component (if applicable):
libpinyin-0.2.99.2-5.fc15.x86_64

How reproducible:

Steps to Reproduce:
1. install libpinyin and enable it
2. input pinyin character "hong mao" (pinyin character for RedHat)
3. press left key to choose correct candidate
4. press space key to commit input
5. input pinyin character "hong mao" again 
  
Actual results:
libpinyin didn't display the result as same as user last commit.  

Expected results:
libpinyin should remember user preference and display correct result.