I noticed this issue in Snowglobe 1.1 and in Second Life Viewer 1.23, anyway, the JIRA asks to indicate only one version. When i cam out my avatar, to see whatever, even not in a far distance, and my cam comes back to my avatar, some prims, in some attachments, become invisible. If i edit them and close the Edit window they appear again. If i just keep the cam near the attachments and don't do nothing then the prims don't appear even i wait for a while. In Snapshot 001 you can see the tiger has no eyes and the brazalet has not spikes, once i edit the attachments and close the Edit window they appear again, like in Snapshot 002. It seems this only affects to some sculpted prims that are not root prims of an attached object.