160GIGHD HIDES DATA OVER 128GIGS WINXP

160GIG HD HIDES DATA OVER 128 GIGS

USING XP PRO, MAXTOR 160GIG HD (NOT OS HD), MAXTOR 80GIG HD (OS DRIVE), EPOX 8K9A2+ MOBO, ATA 133, OCZ PC 3000 256MB DDR, AMD XP 2600 333 FSB CPU, ON HIGHPOINT RAID. NOT USING RAID ARRAY.

FORMATTED DRIVE AT 152GIGS AFTER COPYING 139 GIGS TO DRIVE TRIED TO VIEW FOLDERS. BUT ANYFOLDER PUT ON DISC AFTER 128GIG MARK IS INVISIBLE. IT IS STILL THERE BUT NOT VIEWABLE.
I CAN STILL COPY INVISIBLE DATA TO ANOTHER DRIVE BUT WINDOWS WILL NOT SHOW IT. ALSO DRIVE PROPERTIES READS 152GIGS FOR DRIVE BUT 128 USABLE SIZE. ANY IDEAS?