diff --git a/firmware/common/disk.c b/firmware/common/disk.c
index 2908bec..bf004d6 100644
--- a/firmware/common/disk.c
+++ b/firmware/common/disk.c
@@ -263,6 +263,7 @@ int disk_unmount(int drive)
     return unmounted;
 }
 
+#include "splash.h"
 int disk_unmount_all(void)
 {
     int unmounted = 0;
@@ -270,15 +271,25 @@ int disk_unmount_all(void)
 #ifdef HAVE_HOTSWAP
     mutex_lock(&disk_mutex);
 #endif
+
+    dbg_print_open_files();
+
     for (i=0; i<NUM_VOLUMES; i++)
     {
         if(vol_drive[i] >= 0)
         {
+            int foo;
             vol_drive[i] = -1; /* mark unused */
             unmounted++;
-            close_files(i);
-            release_dirs(i);
-            fat_unmount(i, true);
+            foo = close_files(i);
+            if (foo)
+                splashf(HZ*2, "closed %d files", foo);
+            foo = release_dirs(i);
+            if (foo)
+                splashf(HZ*2, "released %d dirs", foo);
+            foo = fat_unmount(i, true);
+            if (foo)
+                splashf(HZ*2, "umount returns %d", foo);
         }
     }
 #ifdef HAVE_HOTSWAP
diff --git a/firmware/common/file.c b/firmware/common/file.c
index 447b586..4ff4aa6 100644
--- a/firmware/common/file.c
+++ b/firmware/common/file.c
@@ -28,6 +28,8 @@
 #include "dircache.h"
 #include "filefuncs.h"
 #include "system.h"
+#define LOGF_ENABLE
+#include "logf.h"
 
 /*
   These functions provide a roughly POSIX-compatible file IO API.
@@ -60,6 +62,26 @@ int file_creat(const char *pathname)
     return open(pathname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
 }
 
+void dbg_print_open_files(void)
+{
+    bool logfdump(void);
+
+    static char path[MAX_PATH];
+    bool found = false;
+    logf("open files: (*dirty)");
+    for(int  i = 0; i < MAX_OPEN_FILES; i++)
+    {
+        if(!openfiles[i].busy)
+            continue;
+        if(!fat_get_file_name(&openfiles[i].fatfile, path, MAX_PATH))
+            strcpy(path, "<error>");
+        logf("  %s%s", openfiles[i].dirty ? "*" : "", path);
+        found |= true;
+    }
+    if (found)
+        logfdump();
+}
+
 static int open_internal(const char* pathname, int flags, bool use_cache)
 {
     DIR_UNCACHED* dir;
@@ -845,6 +867,7 @@ int close_files(int volume)
     struct filedesc* pfile = openfiles;
     int fd;
     int closed = 0;
+    int dirty = 1;
     for ( fd=0; fd<MAX_OPEN_FILES; fd++, pfile++)
     {
 #ifdef HAVE_MULTIVOLUME
@@ -855,10 +878,12 @@ int close_files(int volume)
         {
             if (pfile->busy)
             {
+                if (pfile->dirty)
+                    dirty = -1;
                 close(fd);
                 closed++;
             }
         }
     }
-    return closed; /* return how many we did */
+    return dirty * closed; /* return how many we did */
 }
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index a4eb24c..40b8c9d 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -2662,3 +2662,25 @@ bool fat_ismounted(int volume)
     return (volume<NUM_VOLUMES && fat_bpbs[volume].mounted);
 }
 #endif
+
+bool fat_get_file_name(struct fat_file *file, char *path, long len)
+{
+    static struct fat_dir dir;
+    struct fat_direntry direntry;
+
+    memset(&dir, 0, sizeof(dir));
+    memset(&direntry, 0, sizeof(direntry));
+
+    int rc = fat_opendir(IF_MV2(file->volume,) &dir, file->dircluster, NULL);
+    if(rc < 0)
+        return false;
+    while(fat_getnext(&dir, &direntry) >= 0)
+    {
+        if(direntry.firstcluster == file->firstcluster || direntry.name[0] == 0)
+            break;
+    }
+    if(direntry.name[0] == 0)
+        return false;
+    strlcpy(path, direntry.name, len);
+    return true;
+}
diff --git a/firmware/export/fat.h b/firmware/export/fat.h
index 1551107..df6f8a6 100644
--- a/firmware/export/fat.h
+++ b/firmware/export/fat.h
@@ -137,4 +137,6 @@ extern bool fat_ismounted(int volume);
 extern void* fat_get_sector_buffer(void);
 extern void fat_release_sector_buffer(void);
 
+extern bool fat_get_file_name(struct fat_file *file, char *path, long len);
+
 #endif
diff --git a/firmware/usb.c b/firmware/usb.c
index aada27d..e5512b3 100644
--- a/firmware/usb.c
+++ b/firmware/usb.c
@@ -77,7 +77,7 @@ static int usb_mmc_countdown = 0;
 
 /* Make sure there's enough stack space for screendump */
 #ifdef USB_FULL_INIT
-static long usb_stack[(DEFAULT_STACK_SIZE + DUMP_BMP_LINESIZE)/sizeof(long)];
+static long usb_stack[(DEFAULT_STACK_SIZE + DUMP_BMP_LINESIZE + 512)/sizeof(long)];
 static const char usb_thread_name[] = "usb";
 static unsigned int usb_thread_entry = 0;
 static bool usb_monitor_enabled = false;