I did a similar hack for a bluetooth GPS (B-Speech GPS20c) ttl wired directly to arduino mentioned here: http://arduino.cc/forum/index.php?topic=106798.0
In running, tinygps v.12 and using sample program "test_with_gps_device". Changing SoftwareSerial.h to _SS_MAX_RX_BUFF = 128 was not enough. With this device and for use with this example program I had to go "256". That's alot for the example and softserial. I think the example should be trimmed down; who cares about the Coarse to London thing.
6 150 99.99951 -999.19108 505 11/13/2012 03:03:33 508 17.20 1.76 0.08 N 7087 43.14 NE 75572 5839 685
Now that I know everything works I'm off to write a program that won't require such a large use of RAM. I hope this helps someone who didn't get all their data populated by using the example sketch.