txpower was disabled for good reason it would appear, it triggers syntax errors in some configurations. Disable it again since it's been disabled for years, and comment out the user-facing config portion for now since it doesn't do anything. Ticket #4516

etc/inc/interfaces.inc

@@ -2416,9 +2416,11 @@ function interface_wireless_configure($if, &$wl, &$wlcfg) {
 	}
 
 	/* handle txpower setting */
+	// or don't. this has issues at the moment.
+	/*
 	if($wlcfg['txpower'] <> "" && is_numeric($wlcfg['txpower'])) {
 		$wlcmd[] = "txpower " . escapeshellarg($wlcfg['txpower']);
-	}
+	}*/
 	
 	/* handle wme option */
 	if(isset($wlcfg['wme']['enable'])) {

usr/local/www/interfaces.php

@@ -2986,6 +2986,7 @@ $types6 = array("none" => gettext("None"), "staticv6" => gettext("Static IPv6"),
 						<?php else: ?>
 						<input name="protmode" type="hidden" id="protmode" value="off" />
 						<?php endif; ?>
+						<?php /* txpower is disabled because of issues with it.
 						<tr>
 							<td valign="top" class="vncellreq"><?=gettext("Transmit power"); ?></td>
 							<td class="vtable">
@@ -3002,7 +3003,8 @@ $types6 = array("none" => gettext("None"), "staticv6" => gettext("Static IPv6"),
 								</select><br />
 								<?=gettext("Note: Typically only a few discreet power settings are available and the driver will use the setting closest to the specified value.  Not all adapters support changing the transmit power setting."); ?>
 							</td>
-						</tr>
+						</tr>*/
+						?>
 						<tr>
 							<td valign="top" class="vncellreq"><?=gettext("Channel"); ?></td>
 							<td class="vtable">