Assuming that US English is your PC language setting I have no idea why SiteAdvisor would suddenly decide it's Spanish. Make sure that nothing has changed those settings. This would happen if you'd downloaded it from a non-US server perhaps.
Thanks for the support Ex Brit! I uninstalled and reinstalled SiteAdvisor. It is still Spanish, but now with English sprinkled throughout (like SiteAdvisor is confused when building the page text).
I have a Benq wireless SPANISH keyboard (yeah - wasn't looking when I bought it, but works perfectly well). I suspect SiteAdvisor is getting confused between the keyboard and the US-based provider (?). The keyboard is set to ES, but the system language is English.
Are you sure that keyboard hasn't a hidden setting somewhere, or a key combo, that switches languages? Also check the following...I am using Vista but the settings are almost the same in XP. (not sure what you have) Double-check Control Panel > Region and Language Settings > Keyboards etc. > Change Keyboards and other input methods > Change keyboards > Advanced key settings > Change key sequence > set that at None so no key combo will alter language settings.
I think you are right - something somewhere is fooling SiteAdvisor.
By this logic, my brand new Microsoft Bluetooth keyboard is made in China, so does that mean I can expect an unpleasant surprise at some stage...I hope not!!
I'll ask to see if anyone can think of a reason for this if nothing above helps. Let me know.