Updating lines 55 to 64 in the jquery.fileupload-ui.css.erb to the following seems to work on Sass 3.2.

richkuo · richkuo · commit daac6ffdde95 · 2012-09-06T22:49:56.000-03:00
/* Fix for IE 6: */
* html .fileinput-button {
  line-height: 22px;
  margin: 1px -3px 0 0;
}




/* Fix for IE 7: */
* + html .fileinput-button {
  margin: 1px 0 0 0;
}
diff --git a/vendor/assets/stylesheets/jquery.fileupload-ui.css.erb b/vendor/assets/stylesheets/jquery.fileupload-ui.css.erb
@@ -53,13 +53,13 @@
 }
 
 /* Fix for IE 6: */
-*html .fileinput-button {
+* html .fileinput-button {
   line-height: 22px;
   margin: 1px -3px 0 0;
 }
 
 /* Fix for IE 7: */
-*+html .fileinput-button {
+* + html .fileinput-button {
   margin: 1px 0 0 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -53,13 +53,13 @@`
`53`	`53`	`}`
`54`	`54`
`55`	`55`	`/* Fix for IE 6: */`
`56`		`-*html .fileinput-button {`
	`56`	`+* html .fileinput-button {`
`57`	`57`	`line-height: 22px;`
`58`	`58`	`margin: 1px -3px 0 0;`
`59`	`59`	`}`
`60`	`60`
`61`	`61`	`/* Fix for IE 7: */`
`62`		`-*+html .fileinput-button {`
	`62`	`+* + html .fileinput-button {`
`63`	`63`	`margin: 1px 0 0 0;`
`64`	`64`	`}`
`65`	`65`