Poor performance with JFileChooser

So quick question for you all, why does JFileChooser have such poor performance sometimes?

It’s not really critical as I’m only using it for the level editor, but occasionally the JFileChooser will hang for almost a minute (rarely more than that). The thing is, this doesn’t always happen. It’ll happen after using the program for a while, or immediately after start up (within 30 seconds), sometimes it’ll never happen, sometimes it always happens. There doesn’t seem to be any consistency.

I’ve heard that certain file associations can mess it up, but I have the path set to a folder with only .lvl files that don’t have an association. These files are are all less than 5mb and it doesn’t matter if there’s only one file or twenty files, sometimes the filechooser hangs sometimes it opens immediately.

FYI, I’m on windows 8.1 pro and I have not tried this on other machines. Any ideas?