Sure sounds like a hardware problem - probably failing RAM, or (less likely) a marginal network card.

Clues:

• Happens with lots of modules loaded.
• "External Exception" message (not Internal) - probably being generated by a hardware interrupt.
• Not occurring on other machines.
• While repeatable, not consistently so.
  

The fact that it has started since the 8.0 versions were installed might either be a co-incidence, or due to the fact that these modules are now larger, and so more internal memoery is being used when they are loaded.