So I have two pages that share the same controller. On the first page you enter you inputs and the second page rendered as a PDF has all of you outputs. Before Spring '09 something like this wouldn't have worked.

It now works fine if you direct a user straight to that page but if you try to get the content of the page and turn it into an attachment it does not work.

Here is the code:

Page 1: pdfCreate
<apex:page controller="pdfIssues">
<apex:form >
<apex:inputText value="{!yourName}"/><br/>
<apex:commandButton value="View PDF" action="{!view}"/>
<apex:commandButton value="Attach PDF" action="{!attach}"/>
</apex:form>
</apex:page>

Page 2: pdfView
<apex:page controller="pdfIssues" renderAs="pdf">
<apex:outputText value="{!yourName}"/><br/>
</apex:page>

Controller:
public class pdfIssues {

public String yourName {get; set;}

public PageReference view() {
PageReference pdf = Page.pdfView;
return pdf;
}

public PageReference attach() {
Id oppID = [select Id from Opportunity limit 1].Id;

PageReference pdf = Page.pdfView;
Blob pdfContent = pdf.getContent();

Attachment doc = new Attachment(
ParentId = oppID,
Body = pdfContent,
Name = yourName +'.pdf',
ContentType = 'application/pdf'
);
insert doc;

return new PageReference('/'+doc.Id);
}
}

If you click the  View PDF button everything works great, controller state is maintained and the PDF is rendered successfully. If you clikc the Attach PDF button you will be returned to the attachment but when you try to view it there will be an error.

This is a simplified example but in my more complex page this is some additional strange behavior. It will execute the Attach() method 4 times and insert four PDFs, non of which can be opened.

-Thanks,

Jason