Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches

Super, that works , but only for hit the next wall :cold_sweat:
When I try to download, I get this error: >> avrdude: ser_open(): can't open device "COM17": The system cannot find the file specified. <<
I know that my COM port are COM17, and I am able to download via the ā€œoriginalā€ IDE
Any ideas ?
/Per