VLAN tagged packets received by application are corrupted

Hi all, I have query on vlan tagged packets received by network interface. Problem: I have application which would receive all packets on the interface and process them ( this could be including vlan tagged packets). However when the 8021q (vlan) module is not loaded and the appropriate interfaces for all the IDs are not created I see that the application is not able to decode them. When we capture with tcpdump/tshark/wireshark as well we see that the packets are not correctly displayed. The Ethernet header type itself is not correctly identified and thus the rest of the packet cannot be decoded. What could be causing this and is there a way to fix this? -- Thanks, -aka