partially methylated? - (Nov/05/2004 )

I am study the methylation with MSP and BMP, after the sequencing, I found sequencing show some CG is methylated , some not, is it normal in the gene's promoter? On my knowledge, I think if we said some gene promoter is methylated , that mean all the CG are methylated, is it right?
Any reply are apprecaited?

Partial methylation usually implies to the situation in which in a mixture of cells or DNA molecules, some are methylated and some are not at a given CpG site. Partial methylation may be due to difference in methylation among cells or among alleles. For example, if you study DNA from one cell, and find partial methylation, that is caused by methylation of one allele but not the other. If you use more than one cells, it is hard to tell if partial methylation is caused by difference in methylation among alleles or cells.

CpG sites within the CpG island of methylated gene may not be equally methylated.