I've already been playing bass for years. My obsticals to learning notation are mostly timing related.

I find that most notation books contain pasages to music that I dont own/can't get/ never heard of. Most of the sheet music that I can buy is guitar or piano related and the bass lines are not as the record.

Ideally I would like to find a tutorial with notation with the actual recording. Even better, a software package which plays in midi and loops it until I get it right.

Can anyone recomend anything?

you could try Musicdojo.com's note reading course. They have exercises, and the teacher puts a recording on right under it. I took it, it's highly recommended. It's kind of stupidly easy at the beginning but they add something new each day, IE 8th notes, next day 16th notes, dotted 16th notes. It made figuring out the timing easier for me even though I am still far from being profecient.

Don't know if it's any use but I wrote out some stuff several lifetimes ago that is now "out on the web":

http://www.vt2000.com/basswork/techindx.htm

It's a series of graded exercises in reading rhythm - from trivial to crazy in 4 easy steps. It was intended to be played with someone listening to help correct your mistakes, but may be of use.

Ian