[Serusers] Could SER-0.9 Be Crashing My ATAs?

Hi All. I'm using ser-0.9 with mediaproxy-1.2.0 We've been trying to track down a problem whereby different ATAs stop working either partially or crash entirely. We have a UTstarcom iAN-02EX with firmware 1.8.2.15a (released a few weeks ago). When I telnet to the ATA and enable debug messages I see this: Not a valid SIP request! Error: Parse error... The above error is generated everytime SER sends a UDP keep-alive packet shown below: 23:35:21.494441 pcp02356144pcs.clbrtn01.fl.comcast.net.5060 > ssvsoho137.smartcity.net.58317: udp 4 (DF) [tos 0x10] 0x0000 4510 0020 69c2 4000 4011 24ee 4454 f278 E...i.@.@.$.DT.x 0x0010 425a 32e6 13c4 e3cd 000c 5c37 0000 0000 BZ2.......\7.... Can anyone tell me if this is a SER issue or not? Regards, Paul