I'm not sure how to begin diagnosing this, but since the upgrade - could be yours, could be mine (my iPhone software was recently updated), the xmarks experience on my iPhone is not the same as in a desktop browser.

It's always been a wee bit different but there are four things that I've noticed for sure:

1. The first three ads across the top don't display
2. Clicking the go-to-last-post button only takes you to the top of a thread, not the bottom.
3. the plain (low-traffic) yellow envelop thread indicator does not display
4. I clicked the quick links drop-down menu and it replaced the items on the menu bar with the items from the drop-down (and there was no drop-down). The link I clicked was functional, however.

Regards,
Rex.