"Resources" is actually a reference to a fixed-length memory segment in Windows where your computer keeps pointers to things it has opened as windows or files. It is the area where "object" structures are kept. When you see references to "handles" in any Help file or API call, the handle USUALLY refers to something kept in the resource area.
In their infinite wisdom, Microsoft made this area exactly 64K in length (i.e. 16 bits) rather than figuring out ways to make it bigger when they needed it. Because of this incredible stroke of genius, a machine with 256 Megs of RAM can still run out of memory in a single application yet still have 128 Megs of RAM open! Because the memory that gets used up faster than any other is "Resources." And you CANNOT do anything to Windows to expand the area, as far as I know. (Not sure about XP, but for anything earlier, I think I'm right on that.)
Then, to make matters worse, none of the MS Office suite is noted for being nice about resource release. They almost ALWAYS hold on to what they've got longer than they really need it. With the unfortunate result that the resources stay reserved longer then YOU really need them.
Things to look for include LOTS of sub-reports, lots of changes of font in a single report (yeah, font files use up resources - each .TTF file has be to open when you process a report using that font). If you have any OLE references, embedded pictures, etc. - more files = more resources.
My best advice would be to look at the report, see just how many different fonts and external objects are involved, then see if you can somehow minimize them. Also, if you have other apps open, CLOSE them if you don't need them. Closing an app usually makes Windows reclaim slots in the resource area. The less your machine is doing outside your app at the time, the more your app can do before it goes belly up.
For more reasons that we can ever know, "simpler = better" when Windows is involved.
