diff --git a/Doc/ChangeLog.txt b/Doc/ChangeLog.txt
index 83247663..bc0a0084 100644
--- a/Doc/ChangeLog.txt
+++ b/Doc/ChangeLog.txt
@@ -16,6 +16,7 @@ Version 3.5
 - L?B: Added support for NABU w/ RomWBW Option Board
 - M?P: Reorganization of Doc directory introducing subfolders
 - WBW: Upgraded BBCBASIC to v5.00
+- W?S: Updated FLASH utility to v1.3.9
 
 Version 3.4
 -----------
diff --git a/Source/HBIOS/cfg_nabu.asm b/Source/HBIOS/cfg_nabu.asm
index a2b940f2..538bc8e1 100644
--- a/Source/HBIOS/cfg_nabu.asm
+++ b/Source/HBIOS/cfg_nabu.asm
@@ -30,7 +30,7 @@ AUTOCON		.EQU	TRUE		; ENABLE CONSOLE TAKEOVER AT LOADER PROMPT
 CPUSPDCAP	.EQU	SPD_FIXED	; CPU SPEED CHANGE CAPABILITY SPD_FIXED|SPD_HILO
 CPUSPDDEF	.EQU	SPD_HIGH	; CPU SPEED DEFAULT SPD_UNSUP|SPD_HIGH|SPD_LOW
 CPUOSC		.EQU	3580000		; CPU OSC FREQ IN MHZ
-INTMODE		.EQU	1		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2, 3=MODE 3 (Z280)
+INTMODE		.EQU	2		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2, 3=MODE 3 (Z280)
 DEFSERCFG	.EQU	SER_38400_8N1 | SER_RTS	; DEFAULT SERIAL LINE CONFIG (SEE STD.ASM)
 ;
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB (MUST MATCH YOUR HARDWARE!!!)
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index 838f99bf..99920627 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -509,6 +509,13 @@ HBX_IDENT:
 ;
 HBX_INVOKE:
 ;
+#IF (INTMODE == 0)
+	; IF SOMETHING IN USERLAND ENABLES INTERRUPTS AND WE ARE NOT
+	; CONFIGURED TO USE THEM, THEN SHUT THEM BACK OFF AGAIN FOR
+	; SAFETY.
+	DI
+#ENDIF
+;
 #IF (HBIOS_MUTEX == TRUE)
 	PUSH	HL			; SAVE HL
 	LD	HL,HB_LOCK		; POINT TO LOCK
diff --git a/Source/Images/Common/All/FLASH.COM b/Source/Images/Common/All/FLASH.COM
index b14d74e3..bd5f0eeb 100644
Binary files a/Source/Images/Common/All/FLASH.COM and b/Source/Images/Common/All/FLASH.COM differ
diff --git a/Source/RomDsk/ROM_256KB/FLASH.COM b/Source/RomDsk/ROM_256KB/FLASH.COM
index b14d74e3..bd5f0eeb 100644
Binary files a/Source/RomDsk/ROM_256KB/FLASH.COM and b/Source/RomDsk/ROM_256KB/FLASH.COM differ
diff --git a/Source/RomDsk/ROM_384KB/FLASH.COM b/Source/RomDsk/ROM_384KB/FLASH.COM
index b14d74e3..bd5f0eeb 100644
Binary files a/Source/RomDsk/ROM_384KB/FLASH.COM and b/Source/RomDsk/ROM_384KB/FLASH.COM differ
diff --git a/Source/RomDsk/ROM_896KB/FLASH.COM b/Source/RomDsk/ROM_896KB/FLASH.COM
index b14d74e3..bd5f0eeb 100644
Binary files a/Source/RomDsk/ROM_896KB/FLASH.COM and b/Source/RomDsk/ROM_896KB/FLASH.COM differ
diff --git a/Source/ver.inc b/Source/ver.inc
index 0b8f3f40..81923253 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,7 +2,7 @@
 #DEFINE	RMN	5
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.5.0-dev.44"
+#DEFINE BIOSVER	"3.5.0-dev.45"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index e1e22fee..bcc13c07 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	5
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.5.0-dev.44"
+	db	"3.5.0-dev.45"
 	endm