I've found a small bug within the shopping cart it seems.
Whenever I move from the page http://www.tapspace.com/basicstrokes.html
to the shopping cart by clicking on "Buy Now" for either the single user or ensemble set I get a page that looks like this:
The basicstrokes page seems to be the only one that causes the error. I have checked some of the other links from the other downloadable sheet music such as http://www.tapspace.com/latinlover.html
and they all load correctly.
I also have no trouble loading basic strokes into my cart once I'm already in the store such as this page http://www.tapspace.com/store/home.php?cat=258
it only happens when linking from basicstrokes.html.
I have reproduced the error in both IE7 and Firefox 2.0.
Just thought you'd like to know.