You must adjust your previous strategy to win. This is a new game. Obviously you were not doing something right if your opponent was able to build that many corvettes without you knowing.  When you see corvette spam you need to build flak. You need to balance your capital ship to frigate as well. 3 Caps is too many  with only 30 corvette.   For the cost of the two capital ships you could have had your flak and easily won the day.   Good luck in the future.

i tryed that as well today... didnt work the guy came back and bit my a$$ but thanks to snakedoc and crimson we won!

Honestly I my favorite solution to corvette spam I've seen was a proposition to turn the battleship caps into Anti-corvettes units by adding anti-verylight flak weapons to them.

Kills 2 birds with one stone(new counter to corvettes & buffs battleships the most underused cap ship class), and doesn't risk gimping corvettes with a nerf in the process.

That said, Flak certainly should get a speed buff(they should counter corvettes a bit harder) and the TEC corvettes really should cost 20-25% more then they do now.  They are every bit as cost effective as the advent ones(and advent are supposed to have more cost effective early game units to compensate for their poor economy in the early game before fleet synergy kicks in).