Actually just crashed again with the same error (aswnet.sys). This is something new for me, all previous crashes were with ndis.sys, so I don't know what has changed in the last day?...
In any case, will have to uninstall Avast for the moment, it's not easy to use the computer when it's BSOD'ing
lol
It makes you wonder how many cases of BSOD'ing are going unreported!
EDIT: Mark one up for randomness! Was going to give it another change but just BSOD'ed again, and after a run of a solid 40 hours without issue. This is really weird, as my usage pattern hasn't changed in this time, and I haven't changed anything else in the system.
Another reason not to downgrade to Windows 8 - it's ugliness isn't just skin deep!