This is still an issue with IF4 trunk rev# 39869, in all browsers (tested with FF26, Chrome32, IE10).
Also, if decreasing the size of the browser window and then maximize it, the table header becomes stretched to the left side of the table as in attached image (chrome-rev39869.png).

This issue has been found also with EE-3.3.0-maintenance branch # 40474 (all browsers):
1) Column Pinning
Columns become miss-aligned after pinning/un-pinning columns followed by re-sizing the window.
2) Dynamic Row Styling via rowStyle Attribute
Columns become misaligned after pinning/un-pinning columns.

It's tricky to apply a row style class to pinned columns. When a column is pinned, it becomes absolute positioned, and since absolute positioning allows us to remove an element from the typical flow, CSS styles and classes are not inherited. That's the same reason why pinned columns aren't highlighted when hovering over the row.

A possible solution that has already been tested is to temporarily set the rowStyle class to all pinned table cells. So far, this works for preserving the rowStyle class, but it overrides the hover highlight.

Committed fix to 4.0 trunk at revision 40913 and to 3.3 EE maintenance branch at revision 40912. Applied the rowStyleClass classes and the hover state class to the child td elements of a row tr element.

Verified with EE-3.3.0-maintenance # 40944 and IF4 trunk # 40946 in FF28, IE10, Chrome34.