[REG 5.5X.->5.6.0]: QTreeView selection highlight disappears in windowsvista-style when using StyleSheets

When using (default) windowsvista style, updating style sheet of QPushButton control breaks the highlight of an item of QTreeView which was active when style sheet was changed.

Steps to reproduce:

• Run the attached program
• Expand item "Text"
• Select item "Text"
• Select item "Text2"

Expected result:
Highlight of the "Text2"-item works

Observed result:
Highlight does not work, even when activating item "Text" again and reactivating "Text2".

The same problem does not happen if after expanding the item "Text" the user selects "Text2" before "Text". This problem is also windowsvista style specific, it is not reproducible with other styles.