Thank you for your post.
I am unable to duplicate the problem, so let me tell you what I did to try and reproduce the problem.
1. I launched FileMaker Pro 10 and created a database file, File1.fp7, with two fields:
2. I entered the following two records into the file:
3. I went to another machine, launched FileMaker Pro 10, and created a second database file, File2.fp7, with two fields:
4. I created a relationship between File2.fp7 and File1.fp7 based upon ID field in both files.
5. While on the second machine, I went into Layout mode and created a portal into File1.fp7 displaying the Name.
6. I went into Browse Mode, entered ID: 1, and TSGal displays in the portal.
7. I turned on Instant Web Publishing with access set to All Users for File2.fp7.
8. I returned to the original computer and turned on Instant Web Publishing with access set to All Users for File1.fp7.
9. I went to a third machine, launched a Browser and entered the IP address of the second machine. I selected File2.fp7, added a new record, entered ID: 2 and clicked Submit. jsutherlin appears in the portal.
I do not have two servers to test out, but it should act identically.
Let me know what else I should try on my end.
I created a test database for each server, setup relationships and enabled IWP. Through Filemaker the cross server relationships work fine but through IWP they still don't. Could this be an issue with Server Advanced even though you got it to work through IWP within Filemaker?