[Xymon] msgs not matching

I'm trying to get a match on a log file string but seem to be struggling.

In my analysis.cfg I have the following, LOG /xymon/server/etc/test.log "%Thread \"WebContainer.{1,75} and may be hung*" COLOR=yellow

On the msgs column on the relevant server I get,

No entries in /xymon/server/etc/test.log

No entries in /tmp/xymontest/ATPReceiptDiag.log

Full log /xymon/server/etc/test.log

Thread "WebContainer : 23" (0000006f) has been active for 686236 milliseconds and may be hung.

Full log /tmp/xymontest/ATPReceiptDiag.log

I've tested my string in my usual regular expression tester and it seems it should work ok.

Is there something obvious that I've missed?