Offline issue tracking system?

http://stackoverflow.com/questions/3657650/where-can-i-find-a-comparison-of-distributed-and-offline-issue-trackers
http://stackoverflow.com/questions/2186628/textbased-issue-tracker-todo-list-for-git

Since our company work on customer's sites,
the Redmine hosted by the company is terribly slow.
And yes, our PM actually uses a huge Excel file for issue tracking.

So, I am looking for a GUI based issue tracking system somehow like Redmine,
which works offline and is able to push change when online.

But there seems no product meet my need...