My buttercream has lots of air bubbles and I don't know what I'm doing wrong. If this topic has been discussed, can someone direct me to the explanation. It's so upsetting.

do a search on air bubbles and buttercream and I'm sure you will find lots of discussions.

I don't have problems with major air bubbles, but here's a few things I do:
Never make a small batch of icing in your KA, fill it past the beaters so air does not get whipped in.
Finish it on stir, and then take a spatula to stir the icing manually.

When I ice a cake, I actually use the cake icer tip, what I have found is that when I place the icing in a large bag, I can push any remaining air out. If there is any air remaining, I will see it when I place the icing on the cake. Yes, the cake icer puts tons of icing on, but alot of it comes back off during smoothing, and I never have problems with crumbs in the icing.

I also use Alpine High Ratio Shortening.

I had a serious problem like this a little while ago.
A few things I did to try and remedy the problem:

1. Ice the whole cake by making up and down "stripes" with the #32 tip (I find this one is better at getting fewer bubbles than others, I think because the ridges are not as deep.)

2. SLOW DOWN when you're smoothing the icing. Use a hot offset spatula or 6" metal drywall putty knife - run it under hot water. Shake excess water off, but no need to dry completely. Smooth very slowly while turning the cake. GO SLOW.

Here's a thread discussing air bubbles in b/c:

http://forum.cakecentral.com/cake-decorating-ftopicp-997951-.html

HTH

This was the first major "symptom" people noticed when Crisco changed their formula around. It absoultely SUCKS, but this followed by it being really runny even if you used less water than usual (and would melt off the cake).. If that's what you're experiencing the problem is the trans-fat free Crisco... Try a different brand but be sure to read the nutrition label and there will be a number listed in the trans-fats to know if it's traditional shortening. Otherwise, I know Sweet Celebrations has started to sell smaller containers of Sweetex because of the whole Crisco fubar..

i was watching food tv and one of the places they were at was making icing....they turn the mixer on low speed but leave it for long..and it mixes the icing with no bubbles...or just little...cant remember which show but they were making wedding cakes.