Thank you for reporting this bug. We will make it our priority to review this report.
Ext JS Premium Member
[FIXED][3.0rc1] File upload button issue
After upgrading to 3.0-rc1 I notice that the button on the file upload example is showing 4 letters: "Brow".
When no letters were visible before.
Can be notice on the example page as well: http://extjs.com/deploy/ext-3.0-rc1/...le-upload.html
Fixed in SVN, you need to set:
Twitter - @evantrimboli