What is the number and letter code description mean on bosch saw blades? for instance pro 1072 sm. what does the sm stand for

Where did you get this code? Was it a dashboard display code or was it an diagnostic Trouble Code? Trouble Codes are longer than this one (one letter and four numbers) and they all have to be there to work out the meaning of the code. Comment below with more information and I'll try to help you more.

A model number is better than a blade size :>)

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Parts List - MasterCraft 055-6742-8 Instruction Manual [Page ...

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MasterCraft 055-6742-8 Manual Online: Parts List. No. Description 1 Screw 2 Locking ring 3 ... 055-6742-8 Instruction Manual. Table saw with fold 'n' roll stand.

put the blade next to ruler and count the number of teeth in the inch measurement
with 6 tpi blade there would be a tooth every 3/32 nch

typically this is a thrust washer issue. need to look at the play between raise and lower..also ensure trunion is cleaned and lubed.

Going on the information aas I read it, the blade is slipping, meaning that it is not tightened enough or a spacer in the hole in the blade is too thick. Make sure that the wall plug is pulled out before attempting any work on the blade.

I couldn't find that specific model number Bosch saw, but here is the link to get user manuals from Bosch in case you mistyped it. (It's a long link that wouldn't all fit here, so I had to put a carriage return in it)
http://www.boschtools.com/Service/ProductServices/Pages/ManualsandPartsDefault.aspx
Or they may have a similar saw under a new model number. Here's the current model number of a very popular saw that has a less-than-obvious blade changing method 1587avsk

this confuses me. What do you mean it starts backwards? How do you know it is running backwards? how long have you had this tool? I am confused because it is a table saw. The motor should drive the blade in the direction the teeth are facing. Meaning the poity part of the blade is where the wood is to star its cut. If this is not the case, you either have the blade in backwards, or your standing on the wrong side of the saw. good luck.

The 1590, like several Bosch jigsaws, has a selector switch to choose the type of cutting action. You have to choose the appropriate cutting action, either straight or oscillating, to accommodate the material you cut and the blade you cut with. For instance, if using a very slender blade for clean curved cuts in wood, a slight oscillating motion ( setting II or III) reduces friction on the blade. 
If you choose the straight cutting action you get maximum accuracy, but drastically increase the friction because the blade is held firmly to the roller bearing.  A slender blade can handle that for brief periods, (say... less than thirty seconds) in soft, thin wood with a straight cut. In hard woods or engineered wood products ( plywood, MDF etc.) the thin blade will heat up and bend. 
You can reduce friction by choosing an oscillating cutting motion, or you can use a larger, sturdier blade. The "Aggressor" blades do not cut as smoothly as the "clean" blades, but they cut faster and are stronger. To cut thick wood ( 4x4 ) or a long cut in engineered material, that is the blade I use. Select number III or number II for 'type-of-cut' and use a bigger blade. See if that stops the "bucking."
Good luck!

If this is a new saw, return it to the store for an exchange, but if it's an older than a few months:

These contractor saws often acquire this problem. It's usually dust, specifically pine dust (it has sap thus making it stickier), on the screw or the sliding mechanism. What I do is:

1. Unplug the saw
2. Remove the blade
3. Dismount the saw from its stand
4. Lower the mechanism all the way
5. Flip the saw over onto its table
6. Access the screw and the lift mechanism
7. Use a brush to remove the accumulated wood dust from the screw and the mechanism.
8. If you have a leaf blower or access to one; blow the interior of the saw (wear eye protection always!)
9. Do NOT oil the mechanism, this will only serve to gum everything up faster - use a dry lubricant (graphite or silicone) or none at all.

To avoid this in the future;

1. Avoid resinous woods (not a likely solution).
2. Blow the dust from the saw interior when finished using it (this works well) - use an air hose or a leaf blower, the leaf blower actually works best.
3. After cutting and before stowing the saw; run the blade to its highest position and then down below the table. This pushes any dust off the mechanism and screw.

If you find little or no dust accumulation, it's possible the saw has a bent screw or binding mechanism and will require service.

Always be safe; unplug the saw and remove the blade when working on it, and always retract the blade below the table when not in use to prevent damage to the blade - or being cut by an exposed blade; they're sharp!

ARE YOU USING BOSCH BLADES IF NOT GET SOME THEY ARE MADE A LITTLE DIFFERENT THAN SOME OF THE OTHER BRANDS AND FIT A LITTLE BETTER , IF YOU ARE THEN DO NOT KNOW