求教：Leonardo总要重新烧写bootloader

FutureMaker

最近用Leonardo，总会出现下面的情况，然后重新烧写bootloader就好了，有人遇到过吗？

Sketch uses 5,502 bytes (19%) of program storage space. Maximum is 28,672 bytes.
Global variables use 153 bytes (5%) of dynamic memory, leaving 2,407 bytes for local variables. Maximum is 2,560 bytes.
avrdude: ser_open(): can't set com-state for "\\.\COM10"
avrdude: ser_send(): write error: sorry no info avail
processing.app.debug.RunnerException
        at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:125)
        at processing.app.Sketch.upload(Sketch.java:1719)
        at processing.app.Sketch.exportApplet(Sketch.java:1625)
        at processing.app.Sketch.exportApplet(Sketch.java:1597)
        at processing.app.Editor$DefaultExportHandler.run(Editor.java:2397)
        at java.lang.Thread.run(Unknown Source)
Caused by: processing.app.debug.RunnerException: Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
        at cc.arduino.packages.Uploader.executeUploadCommand(Uploader.java:111)
        at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:123)
        ... 5 more