navigation system gives wrong directions

[b1doc]

the nav in my '08 suburban wants me to take some really crazy routes to locations (for one example, asking me to exit a freeway and take side streets to an onramp 2 miles down the same freeway, MANY other examples) this occurs both in fasted and shortest modes. When I get very close to my destination then it seems trustworthy, but even then it sometimes says that the address is on the wrong side of the road (I know I can just look at address numbers to figure out which side of the road my destination will be on, but I was hoping that the nav would actually help, no hurt) My Nuvi is always right on spot, so,
1) am I doing something wrong
2)will an updated cd help
3)do I just tape my nuvi over the display and use that
any thoughts?

[Black LT3]

I would try a new nav disc first