Hi
Sorry you are having issues.
Can you try increasing the memory on the server. On a linux server its editing the php.ini file where it says something like memory_limit. Set this number to higher than you have now. On one of the bigger sites I work on its set to 256M. Don't forget you have to restart Apache after for the change to take effect (you may have to ask youtr hosting provider to do this for you)
Doing this has helped others before. Try and let me know if this helps.