help to solve a speed problem with Firebird 1.5

a large Delphi 5 application opens about 25 queries onto a Firebird 1.5 database . IBObjects TIBOQuery objects (v. 4.5) are used to access the db. The more queries are opened, the slower the db access becomes. I did the following experiment: DoSomethingOnDB; // this action takes 1 sec OpenTable1; OpenTable2; OpenTable3; OpenTable4; OpenTable5; OpenTable6; OpenTable7; ... DoSomethingOnDB; // now the same action takes 20 sec !! The same action done against the db is now 20 times slower ! As we are performing exactly the same action, this should put away all guesses about indexes, PKs and (maybe) garbage collection: the response time (slow or fast) should be the same. The point here is that the db response times, after a while, degenerate to unacceptable values. I need help from someone with good experience in IBObjects and Firebird. He will work with me until the solution of the problem is found. Mainly he will remote connect to my PC using LogMeIn (as it would be hard to move the whole db). The solution could well be to expand the PC RAM or whatever.