Sonar 8.5.3 set up line 6 ux2 latency issue

For two weeks the set up of this studio computer has consumed me.  Our computer had crashed, hard drive failure, so I thought it would be good to upgrade the system for my husbands studio.  We got
Gateway FX6840
Windows 7
1TB drive
8gb ram quad core
Sonar 8.5.3
Line 6 UX2 (asio) (using as sound interface)
EZdrummer
Every step of the way has been a nightmare in getting everything 64bit compatible and I thought I had it.  Even did the victory dance.  But here I am again in the studio BEYOND frustrated.    Thank goodness I am in a padded room as the cursing would make Lisa Lampenelli blush!  I need desperate help.
 
Earlier today we finally uploaded a project, 8 audio files, guitar drums etc.  The disk% use went off the charts and caused the system to dropout.  So we moved the buffer size up.  At 256 the disk% was hovering at 40% with only 8 tracks.  We used to have more than 30 tracks in Sonar 8 studio and hardly bump 20%.  So I moved it to 512 like some of the forums recommended.  That put us back to 20% but still not right.  I called cakewalk support and they had me install 8.5.2 and 8.5.3.  As the disk% is a known issue and the 8.5.2 is supposed to fix it.  Same issue.  Called again, they had me uninstall the audio file and let it default back.  Ensured no anti virus running, check, turned off all programs in the startup, check...Same issue.  I sent my system info over and they are supposed to get back to me on Monday.   I've been in performance settings to see if anything was conflicting, nothing.  I've been in power schemes, read that windows 7 has a power conservation that will shut down some of the processors.  AH HA!  nope same issue.  So at that point, thought, what the heck, we can work with it until we get an answer just watching to ensure it doesn't go too high.
 
Then we went to record a new track.  I believe they say "that's when things went from bad to worse".  There is a 4 second delay from when we hit record to when the play line starts tracking and if you start stop say three or four times, it just stops playing all together.  Much cursing again.... 
 
I've seen some folks mention a separate hard drive for audio files.  I never had to do this in Studio 8.  Is this because of 64bit?  The computer I have should bend space and time so not seeing why this would be the issue.  As for the line 6, set up the 64bit patch, line 6 monkey, pod farm 2, gear box, connected the appropriate VST's. 
 
I am sooooo disappointed.  I set up the last system and it was darn near plug an play. 
 
If you have run into this, please let me know what you did to fix it.  Any help would be greatly appreciated.
 
 
 
 
 
 

Thanks for replying.  We got a new UX2 as that is what we had before (but lost the old software), worked great in Studio 8, and we were comfortable with it.  You're right, maybe it doesnt play well with 64bit, windows 7.  I've validated I'm using the 64bit driver and the line 6 folks swear it plays in sonar with the update.  
I went with the biggest hard drive I could find so it wouldn't run out of room and cause issues that way.  Last one we started getting some additional issues/slowness when it was more than half full.  On line it shows the hard drive is a 7200rpm.  
In global/audio it is set to 16, 32 and original (our project wav's were 16 before).  I think 16 should take less room than 24 and move faster.  We are at 44100 so we don't have to adjust later for download.
On the audio options tab (Asio panel) the reported latencies are input 9.3, output 18.6 and roundtrip 27.9.  I have it set on the second to lowest, lowest causes the sytem to not respond.

Here's an idea.  I seem to have more than one driver file. 
C:\windows\system32\drivers\drmk.sys
c:\windows\system32\drivers\ksthunk.sys
c:\windows\system32\drivers\L6UX264.sys
C:windows\system32\drivers\portcls.sys
C:\windows\system32\l6ux2_64.dll
C:\windows\syswow64\l6ux2.dll
 
Maybe one of these should be deleted?

Forgot to mention our windows experienc e is also at 5.9.  :-)