Above and below Thai characters are missing and some are displayed incorrectly

Preconditions or Previous status (If it is setting related error, please provide corresponding settings e.g. IM /MMS error, we should provide server address, account, and related password):

I18n_ui_tester application is installed (sisx files attached).

How did you get to the state just before the error (rich text, step by step):

1. Launch I18n_ui_tester application.
2. Phonebook tab view is active.
3. Press button on the left.

Or
1. Launch I18n_ui_tester application.
2. Calendar tab view is active.
3. Tap on the month name.
4. Check month name in Thai on the list.

Or
1. Launch I18n_ui_tester application.
2. Rendering tab is active.
3. Check Thai characters in rendering view.

Actual result:
Above and below Thai characters are missing and some are displayed incorrectly.

Expected result:
Correct Thai words are shown without any characters missing and they are displayed correctly.

Comments:
Please refer to the attached image files. [Missing Thai characters.JPG, Missing Thai characters1.JPG and Missing Thai characters2.JPG]

Note: Thai above and below characters are also missing from contact name in Phonebook tab view.