diff --git a/CONTROL/control b/CONTROL/control
index 961a7ca..8d9b83d 100644
--- a/CONTROL/control
+++ b/CONTROL/control
@@ -1,7 +1,7 @@
 Package: webif
 Priority: optional
 Section: web
-Version: 1.2.8-9
+Version: 1.2.8-10
 Architecture: mipsel
 Maintainer: af123@hummypkg.org.uk
 Depends: tcpfix,webif-channelicons(>=1.1.20),lighttpd(>=1.4.39-1),jim(>=0.76),jim-oo,jim-sqlite3(>=0.76),jim-cgi(>=0.7),jim-binary(>=0.76),service-control(>=2.1),busybox(>=1.20.2-1),lsof(>=4.87),epg(>=1.2.1),hmt(>=2.0.9),ssmtp,anacron,trm(>=1.1),openssl-command,nicesplice,id3v2,file,rsvsync(>=1.0.2),webif-charts(>=1.2-1),stripts(>=1.2.5-3),tmenu(>=1.08),ffmpeg,id3v2,multienv(>=1.6),tcpping(>=1.1),e2fsprogs,wireless-tools(>=29-1),dbupdate,recmon(>=2.0.7)
diff --git a/webif/html/diag/disk.jim b/webif/html/diag/disk.jim
index a798359..5930835 100755
--- a/webif/html/diag/disk.jim
+++ b/webif/html/diag/disk.jim
@@ -132,7 +132,9 @@ foreach line [split [exec /bin/smartctl -A $device] "\n"] {
 		set notes ""
 		set left [expr 100 - 100 * (100 - $val) / (100 - $thresh)]
 		if {$left < 10} { set class orangeshade }
-		if {$rval > 0 && [dict exists $derive $id]} {
+		# rval can be non-numeric (e.g. 6078h+41m+22.260s)
+		if {[regexp {^\d+$} $rval] && $rval > 0 && [\
+		    dict exists $derive $id]} {
 			if {$left < 100} {
 				set total [expr \
 				    round(($rval / (100 - $left) * 100) \