I guess you need to look in the handling of SNMP in general for this version.

After porting the map from an earlier version, many of the probs fail randomly (no on every device).

This is one of the errors that might relate to this problems, please see image.

I'm seeing similar issues since moving to Beta3.
Device labels and link labels will stop showing OID results. A reboot of our AMD based box will fix it. Not all devices. Seems to be only ones that have Charts also defined.
History for those devices will be blank from the time that it begins until the box is rebooted.

Seems to be about every week or two.