camera Converter

We currently have a 1 m/e complte with Studio converter and 4 x camera converters, mostly working with HD SDI which all works fine, but when we add in an HDMI source into the camera converters the result is somewhat more hit and miss- we have a couple of JVC HD10 EK cameras which we use for locked off shots- sometimes we can just use an HDMI to SDi box for shortish runs and no problems, but after testing all our camera converters- only 1 will allow a full picture back to the switcher. the others give a very soft fuzzy picture with the colours predominantly a green tint.
I have cleaned all the connections etc to no avail- is this a firmware issue on the camera converters?

Hello, i have 3 camera converters and the same probleme.
SONY HD1000E: HDMI > Camera Converter = OK
PANASONIC Z10000 : HDMI > Camera Converter = only 1 will allow a full picture back to the switcher. the others give a problème with chroma color !

glad its not just me then !!
BM- can you help on this??