irldonalb - 10:27 am on Jul 8, 2010 (gmt 0)
maybe it was slow loading, dragging the speed of the page down.
londrum - that's a good point and certainly a possibility. The parent page is flat html and very fast. The iFrame isn't slow but in comparison might be regarded as heavy.
I don't know if this is relevant, or even the correct protocol, but I no follow the iFrame code as the content would be meaningless in SERPS as standalone data.
Simsi - Can you no follow an iFrame? Do you mean you no-follow the links within the iFrame?