Dropping temporary tables version 5.02

I was creating a temporary table and using it to contain the results of a select which included a join with a matches statement. When the temporary table came to be dropped the following error occurred sqlerror -242 could not open database table <owner prefix>.<table name> system error -106 ISAM error:non-exclusive access Everthing works OK on version 4.10 engine, but not on version 5.02. I have isolated it to the matches statement, because other temporary tables are used with no problems. The only work round appears to be using arrays. Matches must be used as the entries in the table contain values such as "123**". Anybody any ideas? Thanks -- Nick Colthorpe