Installation file will not load into Joomla

I have just downloaded TableJX and tried to install in Joomla, but it fails with:

JFolder::files: Path does not point to a valid folder or the folder has been deleted.
JFolder::folder: Path does not point to a valid folder or the folder has been deleted.
JFolder::files: Path does not point to a valid folder or the folder has been deleted.
Error! Could not find a Joomla! XML setup file in the package.

OK - I delved deeper into your site and found I could download a RAR file (never heard of that before) and expand it to get a clean ZIP file. That has installed OK. It would be good if you put the information about possible corruption in IE on the intiial download page (or did you and I missed it?)