Problem only seen in Chrome browser

MarketPress Version 2.1.4
Force login = yes
Buy Now button
Classic Theme
Configured to use PayPal chained payment.

Steps
1. I log out of WPMU first.
2. Use Google Chrome browser to open a product page (I am using Chrome version 14.0.835.202 m for Windows).
3. Click "Buy Now"
4. Next page /store/shopping-cart/, ask for "Login and Checkout" OR "Register To Checkout".
5. I log in and see the following screen:
http://screencast.com/t/7r5PICbeWM
Note: I do not see this if I do the same in IE browser.
6. After I click "go back and try again.", I see the following screen:
http://screencast.com/t/aJXXTMPMEl
7. I have to choose PayPal radio button and click "Continue Checkout".
8. Then next page is normal as I saw in IE (finally)
http://screencast.com/t/KL7xDtjQSq

Why am I seeing that "go back..." message? How can I fix that?

Thank you for reading my question :slight_smile: