MultiLine Tab Control and XP theme drawing

[MrBeans]

Hello All,
I seem to be facing a weird problem with tab control and XP themes. Please find test sample.

Some strange points to be noted:
1) Problem only occurs with 'Multiline' option set on XP with theme drawing enabled
2) Problem only occurs with the tab items on the bottom row (assuming tab control has 2 rows)
3) Problem only occurs if we try to resize the tab control.

It seems that some how a redraw message is not sent to the child windows under certain conditions however force redraw does not seem to help either.

Thanks a lot for the help.