Small-cap stocks mostly underperformed the rest of the market Wednesday thanks to disappointing first-quarter earnings from names like

Arrhythmia Research Technology

(HRT)

.

The Fitchburg, Mass., medical-software company more than halved its per-share income from last year to 9 cents, spurring a 37.3% slide to $12.11.

Goldfield

(GV) - Get Report

, a construction company from Melbourne, Fla., slid 11.8% to $1.05 after swinging to a penny-a-share loss from a 4-cent-a-share profit a year ago.

HandHeld Entertainment

(ZVUE)

, the San Francisco-based maker of Zvue handheld media players, reported one-third lower revenue from last year at $584,000 even while cutting its first-quarter losses in half. Shares receded 10.8% to $1.90.

Also sliding on poor financials was nightclub operator

VCG Holding

( PTT), which was trading down 11.9% to $7.20 after revenue fell just short of the sole analyst's estimate.

JED Oil

( JDO) posted a 23-cent-per-share loss vs. break-even last year, and printer-equipment maker

Media Sciences International

(MSII)

slid to break-even earnings from 4 cents a share a year ago. JED dropped 19.3% to $1.42; Media Sciences fell 9.9% to $5.75.

Among small-cap stocks on the upswing, however, was

East Penn Financial

( EPEN). The Emmaus, Pa., bank soared 66.3% to $13.45 after

Harleysville National

( HNBC) agreed to buy it for about $14.50 a share, or $92.7 million, in cash and stock. The deal will probably close in the fall. Harleysville shares were recently unchanged.

Also climbing on acquisition-related news was

Inter-Tel

(INTL) - Get Report

, purveyor of converged voice-and-data communications systems, after private-equity firm Vector Capital offered to buy it for $26.50 a share in cash. The Tempe, Ariz., company's shares were up $1.34, or 5.2%, to $26.90.

Tecumseh Products

(TECUA)

, a Michigan-based maker of compressors and other products, jumped 12.6% to $12.08 after predicting a second-quarter year-over-year improvement in operating results, despite simultaneously reporting a widened first-quarter loss.

In analyst calls, Citigroup upped Georgia's

Neenah Paper

(NP) - Get Report

to buy from hold, after which shares lifted by 4.6% to $42.72, and Stifel Nicolaus began coverage of semiconductor

Microsemi

(MSCC)

with a buy rating. Shares of the Irvine, Calif., company added 3.4% to $22.

The Russell 2000 and the S&P SmallCap 600, both of which track most of the above winners, were each in the green recently. The former added 0.4% to 817.14; the latter was up 0.3% to 425.56.