After reworking an application in my Designer 8.5 I asked my collegue to test it in his Notes 6.5 client. To my surprise he couldn’t open any document, the only thing he saw was a white screen and an hour glass. Many trials, errors and crashes later, I found out that the older Notes versions have issues with too many subforms.
In my case, “too many” equals 11 subforms. After that, the form becomes from “terribly slow” to “unusable”. Because I didn’t want to lose the advantages of using subforms, I looked around for a solution. I found some answers in this (dutch) post.
It seems that, if you add some code to the subforms (f.e. add an Option Declare in the Global section of the subforms) the issues disappears. The article doesn’t really describe why, but effectively: once I added this to every subform, speed went back to normal!