Does anybody know what to do about this?

Machine is a 2008 Core 2 Duo iMac with 4GB RAM. (And 64bit Debian 7 boots OK, but I've not tried installing under the latest version of VirtualBox as I have just upgraded VBox today.)

VirtualBox 4.3, upon trying to boot a machine with the Ubuntu 13.10 (64bit) iso (with the VM configured for Ubuntu 64bit) crashes, with the following information:

Failed to open a session for the virtual machine Ubuntu64.

The VM session was aborted.

Result Code: NS_ERROR_FAILURE (0x80004005) 
Component: SessionMachine
Interface: ISession {12f4dcdb-12b2-4ec1-b7cd-ddd9f6c5bf4d}

=== Head of crash dump is below

Process:         VirtualBoxVM [716]
Path:            /Applications/VirtualBox.app/Contents/MacOS/VirtualBoxVM
Identifier:      VirtualBoxVM
Version:         ??? (???)
Code Type:       X86 (Native)
Parent Process:  VBoxSVC [644]

Date/Time:       2013-10-17 22:58:23.679 +0100
OS Version:      Mac OS X 10.6.8 (10K549)
Report Version:  6

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000040
Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Thread 0 Crashed:  Dispatch queue: com.apple.main-thread
0   com.apple.CoreFoundation        0x92a25c03 CFSetApplyFunction + 83
1   com.apple.framework.IOKit       0x95557ad4 __IOHIDManagerInitialEnumCallback + 69
2   com.apple.CoreFoundation        0x92a2442b __CFRunLoopDoSources0 + 1563
3   com.apple.CoreFoundation        0x92a21eef __CFRunLoopRun + 1071
4   com.apple.CoreFoundation        0x92a213c4 CFRunLoopRunSpecific + 452
5   com.apple.CoreFoundation        0x92a211f1 CFRunLoopRunInMode + 97
6   com.apple.HIToolbox             0x98eb5e04 RunCurrentEventLoopInMode + 392
7   com.apple.HIToolbox             0x98eb5af5 ReceiveNextEventCommon + 158
8   com.apple.HIToolbox             0x98eb5a3e BlockUntilNextEventMatchingListInMode + 81
9   com.apple.AppKit                0x9971b595 _DPSNextEvent + 847
10  com.apple.AppKit                0x9971add6 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 156
11  com.apple.AppKit                0x996dd1f3 -[NSApplication run] + 821
12  QtGuiVBox                       0x019f19e1 QEventDispatcherMac::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 1505
13  QtCoreVBox                      0x018083b1 QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 65
14  QtCoreVBox                      0x018086fa QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 170
15  QtGuiVBox                       0x01eea9e5 QDialog::exec() + 261
16  VirtualBox.dylib                0x011234b8 TrustedMain + 1108104
17  VirtualBox.dylib                0x01126d68 TrustedMain + 1122616
18  VirtualBox.dylib                0x010fac19 TrustedMain + 942057
19  VirtualBox.dylib                0x010f9b3d TrustedMain + 937741
20  VirtualBox.dylib                0x010f81dd TrustedMain + 931245
21  VirtualBox.dylib                0x010f85b8 TrustedMain + 932232
22  VirtualBox.dylib                0x0109d4f8 TrustedMain + 559304
23  VirtualBox.dylib                0x0101521e TrustedMain + 1518
24  ...virtualbox.app.VirtualBoxVM  0x00002e7e start + 2766
25  ...virtualbox.app.VirtualBoxVM  0x000024b5 start + 261
26  ...virtualbox.app.VirtualBoxVM  0x000023e5 start + 53

====

And please somebody fix the code so that you can just delimit large blocks of code at the start and the end without indenting every line manually by 4 spaces.