Manual scans hang on

I am running CIS 5.10.228257.2253, DB 12066, on XP-Pro SP3.

Last successful manual scans:
Smart - April 07 - duration 2 min 34 secs.
My computer - April 09 - duration 1 hour 05 mins.

Unsuccessful scans:
Smart - April 11, 13, 14.
My computer - April 13.

Manual settings:
scan memory on start;
scan achieve files;
auto update;
cloud scanning unchecked;
enable rootkit scanning;
heuristics level - medium;
do not scan files larger than 40mb.
These settings are unchanged for at least 12 months.

I do not have scheduled scans, and use both smart and my computer manual scans at least once per week.

Example from this morning:
Launched Smart scan, hangs on objects 31,746, and it stayed that way for 45 minutes.
clicked on stop scan > am I sure > yes;
scan continues running, however I right click on the Comodo icon in the task bar, and select exit;
the icon disappears and the scan stops.
CFP.exe and associated services, including CIS helper, are still running.
There are no files in the CIS Data and drwtsn32 folders.

Is there a work-around for this please?

note: my time zone is utc + 10 hours.

Further to:

I have run a smart scan with cloud scanning checked > still hangs on

Could be solved:

Even though CIS updates automatically a couple of times each day, a couple of days ago, I forced a manual update, and then ran a Smart scan.
It was successful.
Next day, I ran a My Computer scan and it was also successful.

Looks like I had a corrupted or missing update fileā€¦