The limit for some considerable time has been about 9223 seconds - and you're hitting a limit much less than that.
Are you using some prehistoric version of ncverilog? What does "ncverilog -version" say?
e.g. simulating "ncverilog testmax.v" where testmax.v is:
always #100000000000 begin
ncsim: *E,TRTOVF: simulated time overflow.
File: ./testmax.v, line = 9, pos = 7
Time: 9223370870978560 PS + 0
./testmax.v:9 always #100000000000 begin