Repair Optimize Tables Messages??
 

Every once in awhile I will "repair/optimize tables" within the maintenance section on the ACP. I always get check-status OK, optimize-status table already up to date.
I received some messages and don't know what they mean or what I should do about them.

Code:
adminhelp Check Warning: 1 client is using or hasn't closed the table properly adminhelp Check Status: OK adminhelp Optimize Status: OK administrator Check Status: OK administrator Optimize Status: Table is already up to date adminlog Check Warning: 4 clients are using or haven't closed the table properly
I would say about 30% of the tables are giving me those various warnings.
Could this be a custom skin or mod issue?
I repeated the process and all warnings have cleared.