X Server 1.15.1 crash when playing Dota2 at or just after picking hero screen

Since I installed this card (GTX 460 1GB 192bits) I’m getting a black screen at some point in the game.
Some times it get recovered if I fast enough doing a ALT+TAB out and in Dota2.
At dmesg log there is a Shader Error.
Computer: Intel® Core™ i7-4770 CPU @ 3.40GHz
8GB RAM
MOBO GigaByte B85M-D3PH
Ubuntu 14.04 LTS 64 bits.
Driver NVIDIA 346.47

########DMESG message:
[13622.300693] NVRM: GPU at PCI:0000:01:00: GPU-5acd8c7b-99b1-e65d-c877-ed569a09f406
[13622.300697] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: Shader Program Header 2 Error
[13622.300701] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: Shader Program Header 3 Error
[13622.300703] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: Shader Program Header 9 Error
[13622.300705] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: Shader Program Header 11 Error
[13622.300707] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: Shader Program Header 18 Error
[13622.300710] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: ESR 0x405840=0xa0040a0c
[13622.300720] NVRM: Xid (PCI:0000:01:00): 13, Graphics Exception: ChID 0009, Class 00009097, Offset 00001a00, Data 00001111
[13627.407660] NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000001 00000080 00000000 00000005 00000006
[13640.927332] NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000001 00000080 00000000 00000005 00000006
[13801.921329] NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000001 00000094 bfef0c11 00000004 00000084
[13868.853266] NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000001 00000094 bfef0c11 00000007 00000000

No idea what could be causing it.

Thanks