Gap In FLR 1 month

This is driving me crazy..
My WP Approval / WP / Visa dates are as under
WP Approval Doc | WP Doc Date | Duration | Visa Date (On passport)
28/11/2002 | 30/11/2002 | 12 months |30/11/2002 to 28/11/2003
24/11/2003 | 27/11/2003 | 6 months |27/11/2003 to 28/05/2004
26/05/2004 | 29/06/2004 | 28/02/2005 |29/06/2004 to 28/02/2005


My first 3 visas are from the same employer (first and then 2 extensions). My fourth visa is from a different employer.

My second work permit extension approval document dated - 26/05/2004 came before finish of previous visa date - 28/05/2004, but my work permit document and visa (stamp on passport) have dates 29/06/2004 almost a month after work permit approval date.

Here is the extract of the contents of letter of extension work permit document for 26/05/2004

“We have approved this application against work permit criteria until 28/02/2005.
Mr<name> has leave to enter or remain in an immigration category that permits him to continue full time employment with you client in the United Kingdomâ€