PAGEIOLATCH_EX Wait type on insert

Hello All,

I am noticing a lot of PAGEIOLATCH_EX wait types whenever there is an insert into a table.  I have the clustered index primary key on a GUID. I wanted to know if this was a disk issue and ran the perfmon for a couple of days with a sampling interval of 2 secs.

I have the

T:\ Drive with tempdb data and log files

M:\ Holds just the data files for few databases

L:\ holds the log files

I:\ holds the error Log

G:\ holds the backups

F:\ holds some data files  

c:\ holds OS and system databases

SQL Server version: sql server 2008 R2 sp1 SE on W2k8R2 sp1 SE

Mem: 32GB

I dont think we have DISK IO issue. Now I am confused on how to tune this query since it is an insert. 

Any ideas?

Thanks for your help