SQl syntax error when I use UNION in my sparql query

[Ryfa]

Hi all,

I'm using arc2 with mysql 5.5.22. But when I use a UNION in my sparql
query it says: "Error: You have an error in your SQL syntax; check the
manual that corresponds to your MySQL server version for the right
syntax to use near 'JOIN arc2store_triple T_0_0_1 ON ( (T_0_0_1.s =
T_0_0_0.o) AND (T_0_0_1.p = ' at line 77 via
ARC2_StoreSelectQueryHandler"

When I used a previous mysql version I didn't have this error. But
when I upgraded the new version i have this error.
My opreing system is Ubuntu LTS 12.04

Best regards,