Aren't you worried about a layer of frozen water condensing on the electronics?
Not really - I only chill it for 10 minutes in the freezer. I guess it gets the PCB to around 5 to 10 °C. Also its winter here at the moment so I will worry about condensation issues later on.
the ideal temperature seems to be between 5 and 10 °C
I tried it again this morning and chilled them for about 10 minutes only in the freezer, then run in ambient temperature of about 18°C
They have been running for about 2 hours now - the 7.75 is actually stable now at 7.98GH/s, the other one is still stable at 7.62GH/s
http://imgur.com/CgQ3YITso now its actually a 960MH/s bonus - just like getting 3 ASICMiner USB for free
(disclaimer - this may have other consequences so research first, and consider your ambient environment)