treo 680 bluetooth connection prblm

I have a treo 680- that used to work with the prius bluetooth- but stopped last week.
although i reapeatedly re-registered - it didnt work (although the registry process went well) it eventually prompted me to delete the telephone Icon with my treo name on it.
on reoeat trials tp re-register- I go thruogh the whole process successfully - with the treo identifying the car and registering it- but the prius does not add the treo and thus I cannot use it

any suggestions?
thanx