diff --git a/mozilla/themes/classic/global/mac/filepicker.css b/mozilla/themes/classic/global/mac/filepicker.css
index 1280a256847..5065f8650e2 100644
--- a/mozilla/themes/classic/global/mac/filepicker.css
+++ b/mozilla/themes/classic/global/mac/filepicker.css
@@ -78,10 +78,14 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 
 .up-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-up.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-home.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
diff --git a/mozilla/themes/classic/global/win/filepicker.css b/mozilla/themes/classic/global/win/filepicker.css
index 98b57254508..0f34f815931 100644
--- a/mozilla/themes/classic/global/win/filepicker.css
+++ b/mozilla/themes/classic/global/win/filepicker.css
@@ -67,15 +67,21 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 
 .up-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-up.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-home.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .new-dir-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-new.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
diff --git a/mozilla/themes/modern/global/filepicker.css b/mozilla/themes/modern/global/filepicker.css
index 069f08b57e7..96842ab6dff 100644
--- a/mozilla/themes/modern/global/filepicker.css
+++ b/mozilla/themes/modern/global/filepicker.css
@@ -70,15 +70,21 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 
 .up-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-up.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-home.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .new-dir-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-new.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
diff --git a/mozilla/toolkit/themes/pinstripe/global/filepicker.css b/mozilla/toolkit/themes/pinstripe/global/filepicker.css
index c977d1eee69..4ecc471664e 100644
--- a/mozilla/toolkit/themes/pinstripe/global/filepicker.css
+++ b/mozilla/toolkit/themes/pinstripe/global/filepicker.css
@@ -63,10 +63,14 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 
 .up-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-up.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/filepicker/folder-home.gif");
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
diff --git a/mozilla/toolkit/themes/qute/global/filepicker.css b/mozilla/toolkit/themes/qute/global/filepicker.css
index 329ab16f4ca..6a49075c635 100644
--- a/mozilla/toolkit/themes/qute/global/filepicker.css
+++ b/mozilla/toolkit/themes/qute/global/filepicker.css
@@ -65,17 +65,23 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 .up-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px 20px 20px 0px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px 40px 20px 20px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .new-dir-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px, 60px, 20px, 40px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
diff --git a/mozilla/toolkit/themes/winstripe/global/filepicker.css b/mozilla/toolkit/themes/winstripe/global/filepicker.css
index cc9794e6c3f..058e4a79a6a 100644
--- a/mozilla/toolkit/themes/winstripe/global/filepicker.css
+++ b/mozilla/toolkit/themes/winstripe/global/filepicker.css
@@ -65,17 +65,23 @@ treechildren::-moz-tree-image(FilenameColumn, file) {
 .up-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px 24px 24px 0px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .home-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px 48px 24px 24px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }
 
 .new-dir-button {
   list-style-image: url("chrome://global/skin/Filepicker.png");
   -moz-image-region: rect(0px, 72px, 24x, 48px);
+  min-width: 0%; // don't let XUL layout min-size override our max-width setting
+  min-height: 0%;
   max-width: 36px;
 }