How many images and how large images do you load?
One reason might be that the drawing has been modified to support more hardware things (T'n'L especially was might not make much of different for regular usage but there are some uses for it).
Also the default flags for loading have changed, you might check the BRL.D3D7Max2D implementation to see in the history how that changed and set it for you manually (especially not using filtered images for example)
One thing that might help is that you change to manuall GC mode on slow systems like your 600mhz system as automatic GC has an overhead (GCSetMode I think and then GCCollect where you used flushmem before).
One reason might be that the drawing has been modified to support more hardware things (T'n'L especially was might not make much of different for regular usage but there are some uses for it).
Also the default flags for loading have changed, you might check the BRL.D3D7Max2D implementation to see in the history how that changed and set it for you manually (especially not using filtered images for example)
One thing that might help is that you change to manuall GC mode on slow systems like your 600mhz system as automatic GC has an overhead (GCSetMode I think and then GCCollect where you used flushmem before).