Can see Bootcamp partition but can't boot it

I tried to resize the Bootcamp partition using gparted. This seems to have killed the ability to boot the Windows partition.

When i boot into OSX Lion, I can see the partition and the files inside it. How can I re-enable the ability to boot from it?

You can't use GParted to expand or contract a Boot Camp partition because it destroys the Windows boot sector. The only application that successfully expands or contracts a Boot Camp partition is CampTune.

Try doing a repair with your Windows CD. Search the MS KB for instructions on how to repair the boot sector. Be real careful though... you don't want to accidentally overwrite or "repair" Lion instead.