Hi Daniel,
As I was about hit 'add reply' I saw that Sven has already provided you a response. Looks like the config settings for both HRP and HRT is correct however, I would like to add/ask one more thing, you mentioned that previously you were getting error message "Vendor is not found for number XXXX" which is a common error if the vendors are set up incorrectly so this means that it was working at some point??
Something has obviously changed something with the search help for vendors - do you know what was changed?? I suggest that you grab a ABAP guy to debug this for a quick turnaround!!!
Let us know if when you resolve this.
Ankur