New DAW setup for X1 - lost all my plugins

I'm in the process of migrating Sonar 8 and X1 to a shiny new DAW but have hit a major snag.

I have copied across alot of the .dll files for my vst instruments but many had to be installed from scratch. The major headache is that when I try to open one of my old projects it comes up with the error message "The following plug-ins are refferred to by this project, but cannot be found. They may be missing or imporperly installed on your system." and then goes on to list just about every important plug-in I use!

The plugs are all working fine when inserted into a new project but older projects don't recognise them. This could mean I'll have to re-load every instrument/effect (and preset!) if I want to play the project.

A chat with CW tech support suggested that it is because the clean install of a VST assigns it a new CSLID number - hence X1 not regcognising it as the existing version of it...

Is this right?
Is there any other way of getting around this?

Any help much appreciated!

It shouldn't matter that that you moved them for the same reason that if you open up the same project on a different DAW (that has the same plugins) the project works. It sounds like something else is wonky. I've found that as long as the plugin name is exactly the same, it just works. 

Only time I've had a problem is when I had both guitar rig 4 32-bit and 64-bit installed on the same machine. It'd ask me which one I wanted to use each time, until I removed the 32bit dll from the vst folder. then all is well.

Thank you for the replies peeps. But I don't know if I'm any closer to an answer.

To reiterate - the VSTscan is picking them all up fine and they are OK to be inserted into a new (or existing) project. The problem is opening existing projects where the instruments are already present. It doesn't associate the plugins used on the old system with the same ones installed on the new system. 

This move is a shift from Sonar 8 (32bit)/Windows XP (32 bit) to Sonar 8 & X1 64bit/Windows 7 (64 Bit) on the new PC1. And I know Win7 uses seperate 'Prgram Files' folders for 32 and 64 bit apps (and hence where my plugs got intalled). But some reading and testing has indicated that it shouldn't matter where the plugs are installed for the old projects to reference them.

 The Cakewalk support page rather ambigiously says:
"This can happen if you're opening a project file that contains a plugin that is not installed on your computer or if your project references a 32-bit plugin and you're using a 64-bit system."

But I thought that the 64 bit versions of Sonar are fine hosting 32 bit plugs via Bitbridge?

Am I missing something here?

This move is a shift from Sonar 8 (32bit)/Windows XP (32 bit) to Sonar 8 & X1 64bit/Windows 7 (64 Bit) on the new PC1.

 
This is normal/expected behavior...
The plugin names are not identical... as they're now either 64Bit dlls... or bridged 32Bit dlls.
In either case, the original plugin name (stored with the project) is not identical... and thus the plugin isn't automatically found/loaded.
 
What you could do is load the 32Bit version of Sonar (along side the 64Bit)
Open up your old project/s in the 32Bit version of Sonar... and save each of these plugin's settings as a preset.  Then... load the project in the 64Bit version of Sonar... and replace the missing plugins (making use of the presets you saved).  A little tedious... but you can work around the issue.  
 
BTW, You'd have this same issue migrating to any 64Bit DAW (not Sonar specific).