Comment 3 for bug 497532

Steps:
   1. setup 2 imap accounts (I'm using SSL on port 993 on one of them. I don't know if this matters)
   2. try to collapse/uncollape the folder list in the sidebar using the left mouse button on the triangle icon
   3. the folder list doesn't collapse/uncollapse <- this is the bug
   4. now, right click on that same collapse/uncollapse triangle icon (this opens a popup menu)
   5. close the popup menu by left clicking somewhere else
   6. goto step 2 (it should work this time)

Steps 4-6 might provide some insight as to why it's broken.