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 01 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 02.