The inside interface is part of the previously existing subnet  - 192.168.90.0/24 - which is Vlan1. The new subnet is 10.52.100.0/24 is Vlan 2. The route to between the two is on the 3560 switch at 192.168.90.4. I am trying to communicate between the two.

If you are trying to communicate between the 2 internal VLANs, it shouldn't even go through the ASA.

You would need to set default gateway for VLAN 1 to be 192.168.90.4 (switch ip address) instead of ASA ip address. The switch should then be configured with default gateway pointing towards the ASA (192.168.90.1).

The Vlans are configured on the layer 3 switch as follows (which I think is what you were suggesting in your prior post):

!
interface Vlan1
ip address 192.168.90.4 255.255.255.0
!
interface Vlan2
ip address 10.52.100.254 255.255.255.0
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.90.1
ip http server
!

With the ASA configuration as originally posted a host attached to Vlan2 is able to talk to the Vlan1 address on the layer 3 switch (192.168.90.4) and the ASA, whic is also attached to Vlan1 via the switch (192.168.90.1) as well as the layer 2 switches in Vlan1. It can also access the internet on the outside interface. That host cannot, however, talk to any hosts in Vlan1.

Hosts attached to Vlan1 can talk to the network devices in Vlan1 but can't access the Vlan2 interface address on the layer3 switch (10.52.100.254) nor can they talk to any hosts in Vlan2.

When I remove the "route inside 10.52.100.0 255.255.255.0 192.168.90.4 1" statement from the ASA the only thing that changes is the Vlan2 host can no longer talk to the ASA or the outside world.

It makes me think that the problem is with the NAT statements but I can't figure out what.

What is the default gateway of hosts in vlan 1?

The hosts on Vlan1 are using the VLAN1 interface address on the switch as their gateway (192.168.90.4)

The host on VLAN2 is using the VLAN2 interface address on the switch as its gateway (10.52.100.254)

You're suggestion provided me with some progress. I went back and double checked and sure enough the gateways for the VLAN1 hosts I was trying to talk to were pointing to the ASA (192.168.90.1). As a result of the change I can now talk to VLAN1 hosts from the VLAN2 host but I still cannot reach the VLAN2 host from the VLAN1 hosts. There are no messages in the ASA log so I'm assuming it is a problem with Inter-VLAN routing at the switch ???

I don't see anything in the log s for the switch but I'm not very adept with switches so I'm not really sure what I'm looking for.

Yes that seems to have gotten it then. Thanks so much for your assistance.