How to debug IE7 silent crashes

Experiencing a problem where a page randomly crashes in Internet Explorer 7 with no warning.

Work-in-progress blog posting, but found this so far:

The crash report requires more Googling it seems:

Access violation - code c0000005 (first chance) eax=00000000 ebx=00000001 ecx=00000000 edx=00000007 esi=00219ec8 edi=00000000 eip=3cf6e923 esp=01e5ddf0 ebp=01e5ddf0 iopl=0         nv up ei pl nz ac pe cy cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00210213 *** ERROR: Symbol file could not be found.  Defaulted to export symbols for C:\W INNT\system32\mshtml.dll - mshtml!DllGetClassObject+bfa45: 3cf6e923 8b490c           mov     ecx,[ecx+0xc]     ds:0023:0000000c=???????? 0:005>