diff --git a/tests/bugs/vis/bug172 b/tests/bugs/vis/bug172
index 323ccbb5c0..94521179ba 100755
--- a/tests/bugs/vis/bug172
+++ b/tests/bugs/vis/bug172
@@ -1,13 +1,13 @@
-puts "TODO OCC29996 Windows: Checking trend failed"
-puts "TODO OCC29996 Windows: Tcl Exception: Memory leak detected"
-puts "TODO OCC29996 Windows: TEST INCOMPLETE"
-
 puts "========"
 puts "OCC172"
 puts "========"
 
 pload XDE
 
+# disable VBO to avoid false memory leaks reported
+# on NVidia graphics, see issue #29996
+vcaps -vbo 0
+
 vinit
 restore [locate_data_file OCC162.brep] s 
 vdisplay s
@@ -23,5 +23,3 @@ for {set i 1} {${i} <= ${i_max}} {incr i} {
     lappend listmem [meminfo h]
     checktrend $listmem 0 1 "Memory leak detected"
 }
-
-
diff --git a/tests/bugs/vis/bug79 b/tests/bugs/vis/bug79
index 72a8ef7a9d..47c313263e 100644
--- a/tests/bugs/vis/bug79
+++ b/tests/bugs/vis/bug79
@@ -2,13 +2,14 @@ puts "========"
 puts "OCC79"
 puts "========"
 
+# disable VBO to avoid false memory leaks reported
+# on NVidia graphics, see issue #29996
+vcaps -vbo 0
+
 vinit
 restore [locate_data_file OCC162.brep] s
 vdisplay s
 
-verase s
-vdisplay s
-
 set listmem {}
 set i_max 10
 for {set i 1} {${i} <= ${i_max}} {incr i} {