1) Windows variant? 32-bit or 64-bit kernel?
Windows 7 x64
2) Intel storage drivers version?
10.0.0.1046 WHQL, 10.0.0.1043 Beta, ICH10R (x58)
3) Disk drives configuration? Any RAID arrays defined?
3 Sata II drives in AHCI, no raid.
1 External via USB (detected instantly)
4) AIDA64 version and build number?
Extreme Edition 1.00.1123beta
I experienced this under Everest Ultimate v5.50.2253beta as well after installing the ISRT 10.1043 beta drivers, and it continues in whql drivers under AIDA64.
The strange thing is, that the smart information is available immediately including the Temperature value.
If i disable Low Level Smart access, the sensors are visible from the start, but the value for the External drive is gone.