Nuvi 765T touch screen

I like my new nuvi 765t very much. The only problem I have is that it does not respond the touch screen function too well. When I wanted to type up, it is not unusual that I had to re-type 3~4 times until I get it right. I had 255WT for a couple of weeks for a try and I do not recall I had such difficulties with 255WT unit. Like I said I like 765T very much but I hate to return it to store because of the problem with touch screen. I calibrated the touch screen a couple of times with not much improvement. Is this a common problem with 765T or just my unit. If I decide to return it to store and get a different one, is there any way to transfer all my data into new unit? thanks for help.