So I did following, enabled logging before if statement and edited ifiles to use just lower case. Replaced ifiles objects. Current logs look like that :
Apr 29 14:04:26 LB01 info tmm[11106]: Rule /Common/irule_SORRYPAGE : HTTP_REQ: Requested Hostname: 10.80.6.3 URI: /sorrypage
Apr 29 14:04:26 LB01 info tmm[11106]: Rule /Common/irule_SORRYPAGE : HTML: Requested Hostname: 10.80.6.3 URI: /sorrypage
Apr 29 14:04:26 LB01 info tmm1[11106]: Rule /Common/irule_SORRYPAGE : HTTP_REQ: Requested Hostname: 10.80.6.3 URI: /background
Apr 29 14:04:26 LB01 info tmm[11106]: Rule /Common/irule_SORRYPAGE : HTTP_REQ: Requested Hostname: 10.80.6.3 URI: /logo