Have to close SmartSnippets to get firmware to run

I'm fairly new to this so I may be missing something.

I compiled the beacon example - I have the expert kit, and then I configured a session in SmartSnippets and download the hex file to the chip using the Booter:

[INFO @14-10-29 16:57:34] TotalIRLen = 0, IRPrint = 0x00
[INFO @14-10-29 16:57:34] Could not measure total IR len. TDO is constant high.
[INFO @14-10-29 16:57:34] Found SWD-DP with ID 0x0BB11477
[INFO @14-10-29 16:57:34] Found Cortex-M0 r0p0, Little endian.
[INFO @14-10-29 16:57:34] FPUnit: 4 code (BP) slots and 0 literal slots
[INFO @14-10-29 16:57:34] BTLE device selected.
(信息@14-10-29 16:57:36]Cortex-M:Debugger tries to set PC to odd value. Corrected register value from 0x20000491 to 0x20000490
[INFO @14-10-29 16:57:36] Successfully downloaded firmware file to the board.

No advertising packets can be seen at this point, i.e. the chip doesn't seem to be running. However, when I close the SmartSnippets tool, or even just go to File->Change Project then the chip starts up and sends out advertising messages. Why doesn't the chip start directly after programming when SmartSnippets is open? Is the JLink holding the reset line low perhaps?

Thanks in advance.