Syntax Highlighting in search results disappears after selecting an entry

[dgrunwald]

1. Open SharpDevelop.sln
2. Search for a common search term that appears in many C# files (e.g. using)
3. Display the search results in 'flat mode' (no grouping by files)
4. Select the first result
5. Scroll through the results using PageDown.
6. Scroll back up using the mouse wheel

Bug: The results that were selected while scrolling down no longer have syntax highlighting.