isolate the old storage in safe way .

I'd like to discribe the current situation then I need your support in short time .

the customer has EMC CX300 conected with two Sql servers containing (windows 2003 cluster ,sql cluster and power path ) .

we have been added new storage CX4-120 in seprate switch and configured some new lun's . now two servers show the old lun's(from CX300)and new Lun's (cx4-140) through HBA cards . each server has twoHBA cards , one card connected with SAN cx300 and another card connected with new SAN cx4-120. i've used the old powerpath and host agent .

I configured the quorum and MSDTC with new lun's ,the cluster working properly . but once remove the old FC cable from card to isolate the old storage , the SQL servers unable to show up new lun's .
my question as follows :

is there any relation between old powerpathe and host agent with new storage (cx4-120) ?
must I remove the old powerpath and instal the new powerpath wth licence in order to see the new lun's ?

really ,Im wondering when I plug again the old FC cable every thing becom good and showing the new and old lun's .

I need method to fix the problem without disrupt the sql servers . and isolate the old storage in safe way .


Thanks .....