You can leave your original installation in place. I suggest unzipping this complete copy of the beta into a new folder, and start it by launching pvrs.exe within that folder. Here's the zip file (about 200 MB):
http://www.softwareforfishing.com/pvrs_ ... 3_2010.zipThe inability to switch between walking and fishing might just be due to being in mouse-look mode, so right clicking to turn that off ought to help. Good advice about approaching the bank at an angle. Your character will only walk up and down slopes to a certain degree of steepness, around 40 degress or so. Taking steeper slopes at an angle or walking along the side slope makes it easier.
Paul