Hello skyW
The issue you're facing happens when you add to many collect data / approval / Feedback steps to a workflow, there is no hard set limit because it's all dependent
on the hardware of the system. I do not have the hardware configuration of your servers however please ensure that this is not due to a resource crunch , may be you want to test the workflow in a server with enhanced hardware configuration to see
if that helps.
I would also suggest reading:
http://support.microsoft.com/kb/2479788
Consider the following scenario:
You create a custom list in a SharePoint Server 2010 site.
You create a workflow for the custom list by using SharePoint Design 2010. The workflow contains at least eight approval task actions.
You try to publish the workflow.
In this scenario, the workflow cannot be published. Additionally, you receive the following error message:
Errors were found when compiling the workflow. The workflow files were saved but cannot be run.
Note The update introduces configuration options to manage this issue.
Thanks ,
Manas