Eheim 2126/2128 with salt water?

[joe reiter <jreiter at bigfoot_com>]

I have an Eheim 2128 thermofilter, and it's truly a great product. 
However, it turns out that the 2126/2128 thermofilters are not 
compatible with salt water, while the 2026/2028 filters (which don't 
have built-in heaters) are salt-water capable.  I'm assuming that it's 
the heater element which is the culprit.  (Perhaps it would be damaged 
by the salt water.)  I looked around and found out that Eheim makes 
special salt-water versions of the 2126/2128 filters.  I'm assuming that 
these salt-water versions have a different kind of heater element which 
can handle the salt.

Does anyone know if my 2128 can be retrofitted to be salt-water safe? 
I'm not sure how to contact Eheim about this, as there are no email 
addresses or phone numbers on their web site.  (www.eheim.com)  Also, 
the 2026/2028 filters are not listed on their site.  (??)  It's not 
critical right now as I'm using it in my fresh water planted tank, but I 
figure somewhere down the road I'd like to also set up a reef tank, and 
I might wish to use the Eheim in that.
-joe