PairGain Technologies Inc. said it has agreed to plead guilty to improper accounting and will pay a $1.4-million penalty related to 1995 investments with a Beverly Hills money management firm. As a result of the faulty accounting, PairGain's books did not accurately reflect the value of its investments with S. Jay Goldinger and his firm, Capital Insight Inc. The money management team lost about $100 million of client funds, including $15.8 million belonging to PairGain, according to a filing with the Securities and Exchange Commission. Tustin-based PairGain said the plea is not expected to have any effect on its present or future business. PairGain shares closed down 31 cents at $9.81 on Nasdaq.