Maximum packet size - roads too big?

I am seeing a crash when a shape is loaded only on a client when playing a client / server game. I have had a suspicion for a while that the mesh roads we are using in our level are getting pretty big. When I change nothing else in the game but just delete some points from our MeshRoad, the crash goes away. Strangely, the crash is not happening when the MeshRoad is loaded though - it is happening when a static shape is loaded.

It looks like the MeshRoad packet is 1338 bytes - I saw somewhere that if you go over 1300 bytes in a single packet you can start to have problems.

Here is the info from the net stats on the MeshRoad:

class MeshRoad net info
   packUpdate: avg (10068.500000), min (9429), max (10708), num (2)
   unpackUpdate: avg (10068.500000), min (9429), max (10708), num (2)
   Mask bits:
       0 -    2 (10068.50)      8 -    2 (10068.50)     16 -    2 (10068.50)     24 -    2, (10068.50)
       1 -    2 (10068.50)      9 -    2 (10068.50)     17 -    2 (10068.50)     25 -    2, (10068.50)
       2 -    2 (10068.50)     10 -    2 (10068.50)     18 -    2 (10068.50)     26 -    2, (10068.50)
       3 -    2 (10068.50)     11 -    2 (10068.50)     19 -    2 (10068.50)     27 -    2, (10068.50)
       4 -    2 (10068.50)     12 -    2 (10068.50)     20 -    2 (10068.50)     28 -    2, (10068.50)
       5 -    2 (10068.50)     13 -    2 (10068.50)     21 -    2 (10068.50)     29 -    2, (10068.50)
       6 -    2 (10068.50)     14 -    2 (10068.50)     22 -    2 (10068.50)     30 -    2, (10068.50)
       7 -    2 (10068.50)     15 -    2 (10068.50)     23 -    2 (10068.50)     31 -    2, (10068.50)

Even if this particular crash is not being cause by the road being too large - are packet sizes over 1300 bytes a cause for concern? It looks like this could limit the maximum sizes of roads.

Keith