Moving from OpenLayers to Leaflet breaks tilecache

Question

My tilecache.cfg is like so (working with MapServer)

[mylayer]
type=WMS
url=http://server/mapserver/app
spherical_mercator=true
layers=mylayer

The following works just fine

var mylayer = new OpenLayers.Layer.WMS(
    "My Layer",
    "http://server/tilecache/tilecache.cgi",
    {layers: "mylayer", transparent: true},
    {isBaseLayer: false, opacity: 0.6, visibility: true}
);

However, when I change the above to Leafletjs like below

var mylayer = L.tileLayer.wms("http://server/tilecache/tilecache.cgi", {
    layers: 'mylayer',
    format: 'image/png',
    transparent: true,
    attribution: 'Data from blah blah'
});

I get the following error

An error occurred: Current y value -5009377.085697 is too far from tile corner y -10018754.170400

Suggestions?

Update2: (top-posted). I tried adding srs definitions (srs:"EPSG:4326" or srs:"EPSG:900913"). While the latter didn't help at all, the particular error I reported above went away with 4326, and a couple of tiles were also returned, though most tiles were just blank. This tells me something is goofy with the way Leaflet expects the projection. I'd rather not change anything on the source (MapServer or Tilecache side), if possible, as other applications are depending on that to be working.

Update: Adding the MapServer map file, in case that might help

MAP
    EXTENT -180.150250417362 -90 180.150250417362 90
    IMAGECOLOR 255 255 255
    IMAGETYPE "png"
    NAME "mylayer"
    SIZE 1200 600
    STATUS ON
    UNITS DD
    DEBUG 3
    CONFIG "MS_ERRORFILE" "/tmp/ms_mylayer_error.log"

    OUTPUTFORMAT
        NAME "png24"
        MIMETYPE "image/png"
        DRIVER "AGG/PNG"
        EXTENSION "png"
        IMAGEMODE RGBA
        TRANSPARENT ON
    END

    SHAPEPATH "/path/to/files"

    PROJECTION
        "init=epsg:4326"
    END

    WEB
        IMAGEPATH "/tmp/ms_tmp/"
        METADATA
            ows_enable_request "*"
            wms_abstract "This WMS mapservice serves a map of mylayer"
            wms_accessconstraints "none"
            wms_title "mylayer"
            wms_onlineresource "http://sever/cgi-bin/mylayer?"
            wms_srs "EPSG:900913 EPSG:4269 EPSG:4326"
            wms_keywordlist "World,mylayer"
            wms_enable_request "*"
        END
    END

    LAYER
        NAME "global"
        TYPE RASTER
        ..

        METADATA
            wms_srs "EPSG:4326"
            wms_name "global"
            wms_server_version "1.1.1"
            wms_format "image/png"
            wms_enable_reques "*"
            wms_extent "-180 -90 180 90"
        END
    END
END

Answer 1

Your map file says you are using epsg:4326 as a projection.

Leaflet map uses epsg:3857 as a default (https://github.com/Leaflet/Leaflet/blob/master/src/map/Map.js)

you could try passing following option when you create your L.Map object

var map = new L.Map('map', { crs: L.CRS.EPSG4326 });

Anyway, your problem is around projections