slipstream sp1 failed to 2k3 Build 3790

[mehargags]

I have got SP1 beta for windows 2003 server but could not Slpstream it. It gave me error " Integrated install Failed. The destination contains an evaluation copy of Windows"

Currently i have the

Windows Server 2003, Enterprise Edition

Evaluation Copy. Build 3790

--Free Downloaded from MS website

After a lil bit of searching i saw u can't apply / Slipstream sp1 on builds prior to "3790 B"

Is my Version Slipstreamable ?

Any Workarounds ????

is there any other updated Version of 2k3 --Paid/free later than my Build?