I think it's a mistake...
Isn't HSDPA : 900/2100 MHz?
If it only works on tmo, its supposed to be something like this... As for an example, Telus/Bell/Rogers (Canada big 3 working on the same frequencies as AT&T) use UMTS/HSPA 850MHz and/or 1900MHz...
Are u sure about this information? i dont know the Vodafone frequencies...