Hello,
That's problem is normal
because Linux can use up to 64 Gigabytes of physical memory on x86 systems. However, the address space of 32-bit x86 processors is only 4 Gigabytes large. That means that, for a large amount of physical memory, not all of it can be "permanently mapped" by the kernel. The physical memory that's not permanently mapped is called "high memory". That's exactly what happens for you.
So recompile your kernel and be careful in the "processor type and features" section to enable High memory support and set the value to 64Gb
Oliv'
