Those who have Mac Pro's and experience PT Error 6085 Please Respond!!!

[speakerboxx]

Sorry to start a new thread about this dreaded Pro Tools error of death.

I read many posts on the DUC and I've gained a lot of knowledge by reading different threads and have used this site as a guideline to making decisions carefully. For those of you who continually provide valuable info for us I appreciate it.

Here is my dilema: Please Bare with me this is a long post.

My current Pro Tools Rig is a Digi 003 Factory with Pro Tools 8. I was using my old 2002 Sony Vaio running PT 8 with Windows and for the most part I didn't have too many issues. My CPU was too slow to handle serious recording especially when I started using Waves PlugIns. I had to upgrade and after months of diliberation I jumped ship from Windows and purchased a Brand New 21.5in. Intel Dual Core iMac. My Waves PlugIns are problematic in SL so I'm running PT using Windows on my iMac in bootcamp. (How Ironic) I'm using Windows XP Pro SP2. To cut to the chase I get the "Underflowed Buffer Message" every min. Trying to record is pointless. I'm using an external glyph hard drive and also an external Lacie Hard drive. Without a shadow of a doubt all my gear is PT compatible both in Windows and SL. I've already done the updates, switched cables, deleted volume and DAE prefs, and done all other fixes. I save my sessions with my Waves Plugs inactive to avoid error messages when trying to open them back up.
I thought it might be a plug in problem but like I stated earlier, I was using the exact same equipment on an old Sony Vaio and had little problems other than processing power. At times PT would not open even after I had just finished a session and tried to reopen it. Saving the sessions with the plugs inactive has solved the problem thus far. So I'm at square one as far as what to do next.

Trust me, I've read very carefully through all of these threads. I thought this was an "operator" problem but I see that many others have the exact same issue.

Basically I'm thinking about ditching the iMac and upgrading to the Mac Pro to run my Digi 003 through a Firewire PCie card. I also see that even people who have purchased a brand new Mac Pro still get the "Underflow Error."
I need advice as far as what to do at this point.
I'm looking for anyone with a Mac Pro and Digi 003 Factory or similar hardware to chime in with any thoughts or opinions. Would running the 003 through the Pcie card alleviate the 6085 error message? I would rather not spend another $1000 to upgrade and still be in the same position. It would be nice to actually finish a session. I think it's pretty pitiful to get happy just because the equipment that you've invested thousands of dollars in actually works. I'm not ready to leave PT just yet but I can't record for more than 2min before the error message pops up. This is a brand new CPU so what gives?
I'm 90% positive that bootcamp has nothing to do with it either. Sorry for venting folks but we all invest time, money, and effort into this. Anyway, for those of you who have found ways to eliminate this "error" please post your thoughts.
Thanks