Help! 75-300 focusing better than 28-135UIS!

After having my 10D with 28-135 for a mere 2 weeks, Ive already gone and bought a 75-300 U mk3 lens, thought I could have some fun with that zoom.

I wasnt expecting super image quality but i was pleasantly surprised. Out of all the test pics ive taken not one has focusing error, the focus point is nice and sharp. This isnt the case with 28-135.

Taking a picture of a face with 28-135
Sometimes if I focus on the eyes with this lens, the nose is not sharp but the ears are very sharp!

Can a lens have a back focus problem? I thought it was camera related.

I cant believe how fast and accurate the 75-300 is.
BTW in two weeks.. ive bought another lens, tripod, camera bag, 380EX speedlight, spare battery, 2 x 256MB.... Im nearly upto my limit on my credit card.. (space for a 1.8 50mm maybe!)

Mrs gonna kill me as she dont know about the new lens!!

I'm in the same boat. The credit card is starting to wheeze from the exertion. I'm hoping for a couple really good pictures to justify the expense before the next statement arrives, otherwise I might be sleeping on the patio for a while.

In my case, there are two lenses she doesn't know about.

Belmondo:

I hope its not the L lens she doesnt know about!!

Im going to ask for a replacement for teh 28-135UIS

Yup. It's the 17-40L (and the 75-300 IS). By the way, I've had very good luck with the latter---handheld, at that! Whenever I'm taking very long shots, I shoot them in burst of 3. Generally, one will be better than the rest. It probably has to do with the shake from pressing the shutter release on the first shot not being present on the next two.

I've taken pictures of freeway signs from over a mile away, and they're perfectly legible. They're just not very interesting pictures artistically speaking.

For me, it's been a good investment.