We can save more and a pile of RAM by eleminating the eqnBVector and EqnAMatrix arrays next.
* UBL G29 -P3.1 mesh fill with distance-weighted least squares fit. * Back to original -O0 on G29 for now.
Also... The memory corruption issue may be fixed. The GCC compiler was inlining static functions and this caused the G29() stack frame to become much larger than the AVR could handle.