I confirm there is a bug in the JMS sharing definition for Kunena that will be fixed in the next release of JMS patch definition 1.2.7.
We hope release it tomorrow and will include other extension definition.
During our Kunena review, we have noticed a problem when Kunena is installed in websites that share the same DB with different table prefix.
We have reported the bug to Kunena and also give them the fixes that must be applied to the latest Kunena V1.5.5.
You can find our post and the description of the bug in their forum at
www.kunena.com/forum/138-support/27726-b...h-other-table-prefix