7.7.0.18 - takes over 10 MINUTES to refresh Activity pane

Tried to use the UI on the prior released 7.6 version. It was so slow, and never returned any data - spinner only - that I decided to check for an update. Having found 7.7 and installed UI and server components, I had my fingers crossed for increased performance.

There are only 12 databases on the active-passive cluster.

6 databases have 5-minutely log backups.

SQL Monitor barfs up a "Long Running Query" Alert for the Activity Pane's refresh activity when the UI is first opened, expand the databases, click the one of interest, and go for LUNCH!

Code:

Low   Long-running query | 4325661     Raised on:   cluster.xxx.xxxx.int\(local) Time raised:   4 Aug 2014 1:18 PM (UTC-04) Details Process ID:   176 Process name:   SQL Backup Database:   master Host:   XXX-DB1 User:   XXX\user Process login time:   4 Aug 2014 1:08 PM Query start time:   4 Aug 2014 1:08 PM Query duration:   600.777 sec SQL process fragment sqbdata

15 minutes and NO DATA = unacceptable.

And it's not like the cluster is overworked, either. There are only 40 jobs, 12 or so of which are SQL Backups and many that only run for a few seconds or minutes every 15 or hourly.

This is a SQL2012SP1CU6 instance on a dual-hex-core Dell R720 with 256GB of RAM, so it's not lacking resources. CPU currently at 16%, 5 waiting tasks, 7MB/sec I/O. Can't see any good reason for this issue other than, perhaps, with msdb at 35GB. there may be a woefully lacking index on one of the core job history tables...

Seriously UNUSABLE interface.

Any ideas, chaps?