Update:
This issue is with regards to multiple pane splitter which was working fine in all browsers except IE9. The widths for the right pane children do not resize accordingly upon window resize.
(In the context of my application, I also had to put the right pane split method in a different javascript thread using setTimeout, 0 delay, otherwise the widths/top positions go wild in IE9.)
Found the problem, which was jQuery .browser.msie conditionals used in jQuery splitter plugin.