C350 unable to Flash with PST

Hi
I have a Motorola C350e
Windows 98
USB interface cable

I am trying to flash my cell with PST 6.7
but having some problemes.
when the cell is ON, it doesnt get detected by PST.
when it is in Flash mode (* # pwr) I get an error :

"Interface Error
Please Power Cycle Phone and Repeat Operation again."

and sometimes :

"Read Phone Info Error
An error occurred reading SEEM_GLOBAL_FLEX_TABLE"

I have installed the drivers for the handset.

can any1 help??

also, how to get out of Flash mode?
the cell doesnt power on when power key is pressed.
I have to remove the battery and put it back to switch the cell back ON.

Thanks.