Comment 2 for bug 1023209

I have the same problem (although haven't tested with the Update Manager icon). All my tooltips appear in the secondary monitor.

System info:

OS:
Mint 13, Maya
Cinnamon 1.4

Workstation CPU:
Dual hex-core AMD Opteron 2427, 2.2 GHz
Supermicro H8DA3-2 MBd

Dual monitors
Nvidia GeForce 8400 GS/PCIe/SSE2
3.3.0 NVIDIA 295.40 (installed using Additional Drivers app)
1 DVI output, 1 VGA output
Primary monitor is set for VGA