Well, I'd try it with OS/2 2.11 then, there is a chance things may work.Given the need to stick with 2.11, my best suggestion is to try the CW-USB drivers at:
http://hobbes.nmsu.edu/cgi-bin/h-search?key=cw-usb&pushbutton=Search
Also, for myself I've had very limited success getting the "USBD.SYS" or "CWUSBD.SYS" driver to properly recognize mass storage devices. There is a modified version of USBD in the MMPORTV1.ZIP file, available at:
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=mmportv1&stype=all&sort=type&dir=%2F
While things may be different, here's what makes it all work in my config.sys:
rem working USB stuff
BASEDEV=CWUSBOHC.SYS /V
BASEDEV=USBD.SYS /REQ:USBUHCD$,USBOHCD$,USBEHCD$,CWUSBUHC$ /V
BASEDEV=CWUSBMSD.ADD /V /FLOPPIES:0 /REMOVABLES:2 /REMOVABLE_AS_FLOPPY /FORCE_TO_REMOVABLE
rem end of working usb stuff
Of course, depending on your chipset, the first line could call the CWUSBUHC.SYS driver.
And the USBD.SYS came from the MMPORTV1.ZIP file.
I think it also needs to have the lastest OS2DASD.DMD driver to work, but I'm not sure on this.
Hope this helps.