Pixelmator won't open files

I have Mavericks running and have completed the application updates for everything including Pixelmator.

Problem is that when I try to open a file using Pixelmator, the files list is not displayed correctly and it is not possible to select or open a file.

Has anyone else encountered this issue and if so is there a solution?

That's the version I'm running.. Do I need to uninstall and retry? If so, just moving the app to the trash bin should let App store reinstall?

After reinstalling, I can open image files from anywhere except my downloads folder. Files in there are not readable by pixelmator even in jpg format.. Is this a bug?

This is happening on both my Air and my iMac, so looks like it could be an issue either with Pixelmator or with Mavericks.