dear Sir,
The said AOP [6SE6400 - 0AP00 - 0AA1] have some memory limitation, but this type of problem is very rear.
however please open the link where you will find lot of information -

http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&cspltfrm=17&nodeid4=20208582&cssw=17&csbinh=0&csquery4=STEP+7+LITE&nodeid0=10805396&lang=en&siteid=cseus&aktprim=0&extranet=standard&viewreg=WW&objid=10803928&treeLang=en

these info will help you to fix the problem.
regards,

 Thanks A lot

Your reply helped me a lot

thanks

Tractor

Hi
This can happen with the AOP, because of all the languages which it has to store, this consumes much of the memory.

To fix this delete one or two of the languages, make sure you delete the ones you do not require!!

Once deleted they cannot be restored......

Refer to the AOP manual, supplied on the CD, page 3 'Memory Limitation'.

To Delete a Language.
Select 'Language' from the top level menue, highlight the language you want to delete then press 'Fn' and (up arrow).

Again please note, once deleted the language cannot be restored..

Thanks for the feedback

Tractor