We worked for a couple of weeks trying to get an STM32F105RCT6 (64 pin, date code 948) to connect to the PC with every possible combination of pull-ups etc.
According to the errata at that time it should have worked. The USART would connect but USB never would. We had the same high current problem on PA9 too.
ST told us many things to try but nothing worked. Finally they gave us a new 952 date code part and it worked immediately.
I would suggest that you get the newest part, based on our experience. We wasted a lot of time on a part that was never going to work.
ST got the part from us so they could evaluate it. They should update the errata sheet to say that parts before 952 may not work with USB boot.
Now we are still trying to get the USB library to work fully but it seems ST has not fixed the issues yet.
At least we can connect to the PC via USB and program the flash now though.
Retrieving data ...