--- a/.hgtags
+++ b/.hgtags
@@ -11,8 +11,10 @@ afc4ee509d9ca3bb4031015c3c22963dcb4b7e7f
 f197b51bbc29a30860e750ee87fd0a047a024f2e FIREFOX_3_1a2_BUILD1
 f197b51bbc29a30860e750ee87fd0a047a024f2e FIREFOX_3_1a2_RELEASE
 269af1ed75649989575d41f53a12048015c6d50e FENNEC_M8
 920a4326d1087b174c2fa2b9a8358e12c697022c SEAMONKEY_2_0a1_BUILD1
 920a4326d1087b174c2fa2b9a8358e12c697022c SEAMONKEY_2_0a1_RELEASE
 f197b51bbc29a30860e750ee87fd0a047a024f2e UPDATE_PACKAGING_R5
 f197b51bbc29a30860e750ee87fd0a047a024f2e -m
 f197b51bbc29a30860e750ee87fd0a047a024f2e Adding UPDATE_PACKAGING_R5 tag in order to make patcher work.
+15cb5d25db054d2d0b56869a2f6351388bfcddcd THUNDERBIRD_3_0b1_RELEASE
+15cb5d25db054d2d0b56869a2f6351388bfcddcd THUNDERBIRD_3_0b1_BUILD1

--- a/browser/base/content/tabbrowser.css
+++ b/browser/base/content/tabbrowser.css
@@ -19,15 +19,15 @@
 .tab-close-button, .tabs-closebutton {
   -moz-binding: url("chrome://browser/content/tabbrowser.xml#tabbrowser-close-tab-button");
 }
 
 .tab-close-button {
   display: none;
 }
 
-.tabbrowser-tabs:not([closebuttons="noclose"]):not([closebuttons="closeatend"]) > .tabbrowser-tab[selected="true"] > .tab-close-button {
+.tabbrowser-tabs:not([closebuttons="noclose"]):not([closebuttons="closeatend"]) > .tabbrowser-tab[selected="true"]:not(:only-child) > .tab-close-button {
   display: -moz-box;
 }
 
-.tabbrowser-tabs[closebuttons="alltabs"] > .tabbrowser-tab > .tab-close-button {
+.tabbrowser-tabs[closebuttons="alltabs"] > .tabbrowser-tab:not(:only-child) > .tab-close-button {
   display: -moz-box;
 }