Note the following information in the S140/S180 release notes:
This image provides support for all S-Series HW classes in a single image.
Prior to this version the S-Series FW was released as three separate images. (An image for the S140 I/O modules, SSA180/SSA150A and S130/S150/S155/SSA130/SSA150).
The multicast capacity for the S130/S150/S155 and SSA130/SSA150 classes has been reduced in this image to allow mixed class compatibility.
Please refer to the multicast capacities section found on page 10 of this note.
An alternate image for S130/S150/S155 and SSA130/SSA150 classes only, with the previous established multicast capacity is available for download