when i launch thunar it take from 5 to 10 sec to initially show the UI, once it has been opened, new instance as well as closing and opening happen fast as one would expect.
This seems to be a very common problem and I am surprised that all these bugs are not rolled into one. I am currently using Xubuntu 3.0.0-15-generic with Thunar 1.2.3. Prior to yesterday's update I had used a workaround found on an Ubuntu forum of changing AutoMount to false in /usr/share/gvfs/mounts/network.mount, which worked. Since the latest update, this no longer works and I get the 'Launch error' message shown in other bug posts here.
*** This bug has been marked as a duplicate of bug 7373 ***