PXA_NO_SHARED_MEMORY

Hello everybody....I am a newbie into this Basis thing, and i have been playin around in SAP, but now i have this issue on our productive server...

Our system is running normally, but.....when some users are runnig huge reports the server just collapses.....and when I look into TX-ST22 I see some errors refering to PXA_NO_SHARED_MEMORY....

I have read in the detail error and I saw that the ABAP program tried to run, but needed 300000KB of memory...then below I also saw that the current is 287, something....so it does not match the 300000that are required by the ABAP Program...so i guess this is the main cause of the NO_PXA error....

by the way I am running Windows 2003 x64, 16 GB PHYS_MEM, and a 65GB page file...

around 25 WP on SAP, don't know what else you need to know in order to have a better idea on how to help out...

thanks in advance...