How many Jaguars do you have on your bus?
How long is the total length of your CAN cables?
Check out Table 8-1 "CAN Wiring Parameters" on page 26 of the
MDL-BDC24 Getting Started Guide. It states the total length of cable should be 20 ft or less. Start with 20 ft of cable, and cut all your cables from that length.
Also, make sure that your terminator resistors (in the RS232 housing and at the other end of the chain) are both 100 ohms.
And, no, it doesn't matter, except for RS232, which side you plug a CAN-only cable to.
Hope this helps!
-David