Everytime I cold start my computer. I open sonar. Open my project and press play. BAM...it crashes. It says "Unhandled Expection." The faulty module is claimed to be SonarPDR.exe. This happens to any project on cold start. My solution to ridding the bug is a workaround... Each time I open sonar I have to open a blank project and save it...Then I open the desired project and it works flawlessly. What Gives?! This problem has always existed on my Win 7 systems and im tired of it. This problem is entirely nonexistent in Sonar 8.0. Any ideas what might be causing it and how to fix? Thank you guys!!! Reinstalling Sonar does not thing...this problem existed since the beginning.
 
Here is the rundown of my systems I use. (All are using Sonar 8.5.3 32bit [couldnt get 64 bit to work at all on my systems]).
 
1. Dell Inspiron N5040 Win 7 64 bit SP 1 Focusrite Saffire 6 USB--- CRASHES on cold start when pressing play. Have to perform workaround.
2. ASUS eee PC 1005PEB Win 7 32 bit SP 0 Focusrite Saffire 6 USB--- CRASHES on cold start when pressing play. Have to perform workaround.
3. HP Desktop Quadcore Win 7 64 bit SP 1EMU 1212M PCI ---- CRASHES ON cold start when pressing play. Have to perform workaround.
 
For each of these systems I have to perform the "workaround" described above to get my projects to play.
 
4. Dell Inspirion 530 Desktop Windows XP 32 bit with EMU 1616M --- ZERO PROBLEMS...Never had a crash ever for anything.
 
Thank you...any help is greatly appreciated.

The key to solving this mystery will be identifying the module that raised the exception. Windows tells you it's sonarpdr.exe, but that's because the actual culprit is some piece of software running within SONAR and sharing its address space. The only way to find out which module is actually raising the error is to analyze a crash dump. SONAR will automatically create a minidump file in \documents and settings\{user_name}\application data\cakewalk\sonar 8.5 producer\minidumps. Open a support ticket with CW and send them the minidump file. They will analyze it and can usually tell you where the error is actually being raised.

Here is the rundown of my systems I use. (All are using Sonar 8.5.3 32bit [couldnt get 64 bit to work at all on my systems]).

That tells me you have something wrong with your systems (except the Asus since its only 32-bit Windows) if you couldn't get 64-bit Sonar 8.5.3 to work at all. 

You need to run a full memory and a full anti-virus test on all of those systems. You can blame it on Sonar until the cows come home, but no one else is having the same problem, so I'm afraid its your system(s) or equipment. I'd work on one at a time to find the problem.  

As bitflipper said, send the minidump to Sonar (see the sticky at the top of the forum) and they may be able to identify the real culprit. 

You may also want to check to make sure your computer has the latest version of the C++ Runtime module. That could cause this kind of problem if you have multiple versions on your computer. From what I've read, its caused when two modules try to access the same memory at the same time. You can get the latest versions here: http://www.microsoft.com/en-us/download/search.aspx?q=c%2b%2b+runtime+redistributable+package 

I'd start by getting the latest Sonar update, I think 8.5.33 is the last incarnation. 

I read about a lot of issues with x64 Win 7 SP 1 and decided not to install it myself. Maybe you could roll that back on one of those systems and see if that solves the problem.

When you Save a blank project and then open the desired project - are they both open at the same time? That would suggest that a needed change is being made to the current session by the Save operation but I can't think what that might be. 

What happens if you open the desired project and Save it before pressing Play?

Is there anything inside the project that could be blamed, a vsti or other plug?