Thanks for your help so far with this.  Given that SimplePress normally works with Woocommerce, I decided that it’s probably a specific configuration issue I have, probably around another plugin too, rather an issue with SimplePress per se.  So I hired a developer to take a look at the situation across the whole site and with all the plugins and they seem to have been able to resolve it.  Still testing, but thanks again for the help with this issue.  I realized it’s an issue that falls outside the help you guys should need to provide.

Derek

Would be most interested to know what they found if possible…

I’ve been digging into their fix and it’s not quite as elegant as I’d like.  I don’t think they really got to the bottom of the exact issue, other than that when deleting a previous plugin some rewrite rules were left over which conflicted with other ones.  Unclear why the forum was triggering this.  But they basically rigged a flush rules to run whenever loading certain plugins.  This works, but will be memory intensive.  I’m working on getting a better solution, but right now it’s just this workaround.

Derek

Yes – it will work and it is fairly quick but it’s not an ideal fix I agree. Has to be a better way.
We did do a lot of checking and we are not flushing rules on each page load so we can think of no reason for rules to be lost…