I used an Eye-One pro, rev B.
Can you explain what you mean by Make a white patch ? Do you mean measure the a white section of paper ?
Or do you mean create a white patch in PS and then convert it to the printer profile and use the PS dropper to measure the LAB values ?
If I do have a OB issue, can you suggest any solutions ?
-->I have asked GMB about this and they blaimed optical brightners in the paper, but offered no further help.
That's what I suspect. What device did you use to measure the paper?
Make a white patch and convert using this profile. What's the LAB values? If the b* value is a negative value, its another indicator that you have an OB issue.