Restriction digestion problem!! - XbaI digestion (Oct/22/2003 )

Hi!

I am having a problem with XbaI digestion. The site was dam methylated earlier, but I have modified the site and it shouldn't be dam methylated anymore. Have also checked it by sequencing, but XbaI is still not cutting!!...Any ideas/comments on what could be happening?? Thanks.

I know hear comes a really really stupid suggestion:

sometimes the overlapping methylation site is only indicated at the 3' end. ie in NEB. but it also counts for the 5' end so for Xba1 no tctagaTC but also no GAtctaga.