I installed Eclipse 3.6 64-bit on a fresh Windows 7. I tried setting some key bindings using the Keys section of the preferences window, namely:
Alt
All eclipse workspace settings are stored in <eclipse-workspace-name>\.metadata\.plugins\org.eclipse.core.runtime\.settings
folder. So, try copying this folder from your 32bit Windows XP environment into 64bit Windows 7 setup.
It may be due to this breaking change in Eclipse 3.6:
http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.platform.doc.isv/porting/3.6/incompatibilities.html?view=co#objectContribution
EDIT:
Looks like it definitely is. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=309074. Here's the fix:
In the "Customize Perspective" dialog, go to the "Command Groups Availability" tab and check "Team" and "SVN".
In Eclipse Mars.2 (4.5.2) this is under Window->Perspective->Customize Perspective... dialog, "Action Set Availability" tab. (Try to restart Eclipse if it doesn't work after you change it). Customize Perspective dialog screenshot