Can't install updates 1-3 for AutoCAD for Mac 2011

[yrendon1]

My AutoCAD keeps crashing so I researched and downloaded the three updates mentioned in all previous streams.  However, after attempting to install update 1 I get this message:

you do not have a copy of autocad installed which can be updated

What can I do now?  My AutoCAD is unusable.  It crashes on its own randomly after being open less than 2-3 minutes. I have this version: 18.1.49.602

I tried installing Update 2 because I thought I may have already been updated but it says it needs Update 1.

Also, I'm running on MAC Lion.

Help please!

BTW, whenever it crashes, I send the error report and not once, in six months, have I gotten a single reply.

[maxim_k]

HI,

If you have E.49.H.602 version, then you already have installed all 3 Updates.

Does AutoCAD crashes in specific situation or with specific files? Or it crashes even if you don't do anything in it after launching?

Maxim