Problem with Installation through Market

install market by the following mwthod then it will work

>open root explorer
>mount system as r/w
>copy the market.apk to system/app using a root explorer
>long hold the file after copying and select permissions in the options
>give permissions like this or refer the attatched image for permissions
read write
read
read

>reboot

try this and tell me if it works or not

 

better then that is do hard reset and have a backup of apps through titanium backup.
Is the market a system app now or still user after the above method
and try to install new version of market

 

Hey no need of that.....just go to settings --> PRivacy -- > Factory data reset..... !!! that's it it has happened to me many times no needto switch back....!! JUst make a contacts data backup before that

 

I think you are rooted already and you have already made a decision to flash stock rom so just give this a try first.
Just do the same what sam told you.rename the apk to Vending.apk and put that in /system/app and give permissions as explained.
Delete a file named "system@app@Vending.apk@classes.dex" from /data/dalvik-cache
Delete a folder named "com.android.vending" in /data/data
Then reboot the phone.Make sure you have backed up the rom or you have stock rom by now and you have clockworkmod recovery installed already to flash the rom if anything goes wrong.

 

As always, happy to help...
And about Factory Reset, if u have deleted something from /system/app, it won't come up again by factory reset.it just formats /data