Preview pane not working in gmail

[Sheridan]

Bit of an odd one, we use GAFE and a lot of our users enable one of the Labs called Preview Pane (does what it says, split screen preview) and it causes no problem.

 

Recently it has stopped working for just one user. The preview pane simply says no conversation selected - and if you click an email it stays the same. Effectively you can't use the email windows until you disable the lab function. When you go into settings to disable the preview pane, you get an error saying on of the functions failed to load. Once you click past the error, disable the preview lab function and reopen your email you can use it as normal.

 

This happens only to one user, but no matter what machine they are on, but only happens in Chrome! Is their GAFE account storing something somewhere that could be causing this? It can't be a local issue as we don't use roaming profiles, and we've recreated the users local profile a couple of times.